question about cam solenoid voltage

[fastboatster]

Long story short, I suspect that there's a short in my wiring harness. I have measured the voltage at one of the cam solenoid connectors with the ignition on and engine not running and got about 7.5V. When I checked the voltage drop between the positive terminal of that connector (yellow and red wire) and a strut tower ground connection, I got 11.7V (that's okay, the battery is very discharged). Also, I have checked the voltage drop between the negative terminal of that connector (it is connected to ECU directly) and the strut tower and got 4.2 - 4.5V. Given that ECU is using PWM to control that solenoid, I'd expect that there would be no voltage at that pin, and it would probably either be connected to the ground or not. Can somebody with B8 (but B8.5 is probably the same) please disconnect either of cam adjuster solenoid connectors (driver side is very easy) and check the voltage at that connector and its pins versus the ground with the ignition on and the engine not running?

[fastboatster]

well, https://www.picoauto.com/library/aut...d-tests/single says that

The Variable Camshaft Timing (VCT) solenoid is an actuator. It is commonly supplied with an ignition live (15 V) and a duty cycled ground provided by the engine management control unit. It has a duty cycle control from the engine management control unit.

I don't think that 3.0T ECU is any different, i.e., varying voltage on the ground side, so 4V there is definitely a problem.

[Smac770]

Correct, N205 on the CCBA should see 12v from the fuse at pin 1, and then the ECM grounds pin 2 to create the voltage drop to actuate the control valve. It is PWM, but don't know what frequency basis is used. You'd need to put the two pins on a scope and graph the voltage drop to see what's going on. But I suspect if the engine is not running, it's not trying to actuate the solenoid. So you should see pin 2 "floating", no connection. And no measured voltage drop from pin 1 to pin 2.

If the harness plug is disconnected, the resistance measurement across the two pins of the N205 itself should be:

• SPECIFIED VALUE: 5 – 20 Ω (+/- 3 Ω @ approx. 20° C).

And then the typical spec for the harness plug back to the ECM plug:

• CHECK: Camshaft Adjustment Valve 1 - N205- harness connector terminal 2 to the Engine Control Module - J623- harness connector T60 / 54 for resistance.
• SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω).

With the plug disconnected, there's no voltage source to the wire. It should read open circuit or 0V at all times, ECM grounded or not. If there's any voltage being measured, the ECM is sourcing it or, as you suspect, a short exists. But to really validate that, you'd need to pull the 60-pin off the ECM.

[fastboatster]

Correct, N205 on the CCBA should see 12v from the fuse at pin 1, and then the ECM grounds pin 2 to create the voltage drop to actuate the control valve. It is PWM, but don't know what frequency basis is used. You'd need to put the two pins on a scope and graph the voltage drop to see what's going on. But I suspect if the engine is not running, it's not trying to actuate the solenoid. So you should see pin 2 "floating", no connection. And no measured voltage drop from pin 1 to pin 2.

If the harness plug is disconnected, the resistance measurement across the two pins of the N205 itself should be:


And then the typical spec for the harness plug back to the ECM plug:


With the plug disconnected, there's no voltage source to the wire. It should read open circuit or 0V at all times, ECM grounded or not. If there's any voltage being measured, the ECM is sourcing it or, as you suspect, a short exists. But to really validate that, you'd need to pull the 60-pin off the ECM.

yeah, I have measured the valve (8Ohm), wires between the valve and ECM and corresponding relay terminal. Haven;t measured the resistance between the connector plug terminals, might be good to do.
Not sure what the ECM does before the start, if it tries to keep the valve open (not sure if it's normally open). The whole issue came about when I replaced an old valve (7 Ohm) with a brand-new OEM 8Ohm valve, then it started to throw cold start timing code on that bank, P0052A or C. I may or may not recall if I have measured the voltage on the N205 plug before, I think at that time I got 1.5V less than battery voltage.
I'll also try to inspect the wiring near ECM and fuse box closer.
P.S. didn't see any chafed wires or damage near ECU or fuse box, must be some other area like wiring harness brackets at the back of the engine

[Smac770]

All is good, replace object X, now have errors. Object X would seem to be the lead suspect. The VVT valve for the B8.0 CCBA 3.0T is 06E109257L, for both banks. I'd just swap them and see if the error stays or moves.

Curiously, the B8.5 CGX/CTU 3.0T uses a different valve, 06E109257N (then S, then T, now AC). S also replaced rev M, no idea what that was used in. But it did not replace rev L for the CCBA.

[fastboatster]

All is good, replace object X, now have errors. Object X would seem to be the lead suspect. The VVT valve for the B8.0 CCBA 3.0T is 06E109257L, for both banks. I'd just swap them and see if the error stays or moves.

Curiously, the B8.5 CGX/CTU 3.0T uses a different valve, 06E109257N (then S, then T, now AC). S also replaced rev M, no idea what that was used in. But it did not replace rev L for the CCBA.

I actually have CGX engine in my car now, so I got 06E109257AC valves in it now since these were brand new (and expensive for what they are, I should say) I had this strange thing going even when I had a replacement CCBA in the car, that's when I first noticed that it didn't "like" 8 Ohm cam solenoids and would throw P052 codes. I tried 06E109257L valves, these can be installed although can't be bolted up in place, those with 7 Ohms "work", but 8 Ohms don't work. Moreover, I have tried a different ECM as well. Back to testing.

[fastboatster]

Checked the wiring in the engine bay some more, I removed the false firewall to get a better look at the wiring at the back of the engine. Looks like the oil pressure switch connector wires at OFH were missing some insulation and got twisted together, they definitely made contact. one of these wires goes to some ECU ground, and another one goes to the body harness. I wonder if this is what caused camshaft adjuster solenoid switchable grounds to go positive. I'll try to make some measurements soon.

[Smac770]

"plenum chamber wall" is what Audi would call it. The plenum chamber is where the battery used to be, etc.

The F22 switch is on the oil filter housing itself, the F378 is next to the oil filter housing.

Assuming a CGXC engine, ECM, and harness, the F22 is powered by the ECM and grounded by the ECM, on a sensor ground that includes a number of devices. The F378 is powered by the ECM, but grounds to the engine metal. So I assume you mean the F22 switch.

The brown/green is a ground line, but I'd expect issues with the other sensors on the ground line (intake manifold flaps, gear detection sensor, brake servo pressure sensor) more so than it messing up the grounding circuit for a separate ground control circuit. But anything is possible inside the black box.

[fastboatster]

"plenum chamber wall" is what Audi would call it. The plenum chamber is where the battery used to be, etc.

The F22 switch is on the oil filter housing itself, the F378 is next to the oil filter housing.

Assuming a CGXC engine, ECM, and harness, the F22 is powered by the ECM and grounded by the ECM, on a sensor ground that includes a number of devices. The F378 is powered by the ECM, but grounds to the engine metal. So I assume you mean the F22 switch.

The brown/green is a ground line, but I'd expect issues with the other sensors on the ground line (intake manifold flaps, gear detection sensor, brake servo pressure sensor) more so than it messing up the grounding circuit for a separate ground control circuit. But anything is possible inside the black box.

yes, it was an F22 switch on the OFH (oil filter housing). I probably should have brought up that I have a code for bank 1 intake manifold flap sensor - voltage too high.
P.S. yes, fixing F22 switch short helped with intake manifold code, but had no effect on cam adjuster solenoids, still see about 4V on each of the ecm controlled pwm ground terminals.
Another thought, what does that capacitor Audi calls "suppressor" do?

[fastboatster]

haven't solved this issue yet, but was able to find out that both upstream O2 sensors had bad grounds (and they still do, I saw about 2V on each of these at the ECU connector) and all the rest of the grounds at ECM connector were fine. trying to solve this issue with O2 sensor grounds, that might or might not lead me to the short which is causing cam adjuster solenoid voltage problem

[fastboatster]

And still haven't solved this issue
I have tried to replace the entire engine wiring harness, not too pleasant of a job with the drivetrain in a car. Putting the harness from the original engine had no effect at all.
Then I realized that some of the engine grounds are coming from the body harness - I had a shorted F22 wiring which is not connected to ECM and goes directly to BCM1 (J519 I believe is the correct name) and that caused a code for the passenger side intake flap sensor voltage. I noticed that I have an occasional code for G395 "implausible signal AC pressure and temp sensor" plus some amplifier code (actually, an amplifier short). I didn't get to the amp yet, but I have measured the resistance between the ground and voltage supply wires of that sensor and found that it's about 22 Ohms. That resistance stayed the same when I removed the J519 module from the car but became infinite when I pulled an SC12 fuse on the fuse panel 1 - fuse 12 on the black fuse terminal holder near driver side door. Measured the resistance between the "supply" point of the fuse socket and G395 ground at the socket - 22 Ohms. Measured resistance between the "supply" point of the fuse socket and the engine ground on the left strut tower - also about 20 Ohms.
So it looks like the wiring to the fuse holder (one big wire for several fuse sockets on the black fuse panel) is shorted to the ground somewhere, or perhaps the short is even somewhere in the wiring from the battery to the cabin. Perhaps I can measure the resistance between the ground and supply for some other sensors not powered by the fuses with the same supply wire. And need to disconnect the amp.
Speaking of positive terminal wiring between the battery and the engine/cabin, where does it run? Is it under the car or running through the cabin? isn't it on the left side under the car?

[Mfryman1]

"So it looks like the wiring to the fuse holder (one big wire for several fuse sockets on the black fuse panel) is shorted to the ground somewhere,"
Just a thought, you are commenting that 22 ohms is a short if I am reading this correct. What I would do next is to read the resistance and pull the associated fuses one at a time and see if you can narrow down the circuit that has the resistance.

[fastboatster]

"So it looks like the wiring to the fuse holder (one big wire for several fuse sockets on the black fuse panel) is shorted to the ground somewhere,"
Just a thought, you are commenting that 22 ohms is a short if I am reading this correct. What I would do next is to read the resistance and pull the associated fuses one at a time and see if you can narrow down the circuit that has the resistance.

yes, I think that 22 Ohms between the ground and positive supply wire is a short (these are not connected via battery since it's also was disconnected at BOTH terminals and all the consumers are switched off).
Yes, I think I can try to find what other fuses are connected between that wire and the battery and see which fuses, if removed, cause that resistance go to infinity

[Smac770]

"that some of the engine grounds are coming from the body harness"

Some devices have their grounds provided from a control module. But I would not call them engine grounds.

Yes, the F22 is not on the J623, it's on the J519. The sense wire is connected to the J519 through the ECM box 17-pins, but the ground wire is spliced to the engine harness ground lines and grounds to the engine bay left. The reduced oil pressure switch is monitored by the J623 directly. The F22 wire path passes through 17-white pin 9. The 17-white (T17r) and 17-red (T17q) connectors in the ECM box are pass-throughs for the interior wiring harness to the engine and engine bay harnesses. For example, the wires for the N119 servotronic wires and the N280 AC compressor activation solenoid wires. Even the alternator VR LIN bus line passes through those.

Not sure I follow the measurement of the G395. It's not a passive RLC object, it's a LIN bus slave and pressure measurement integrated circuit device. You can't measure anything "across" the G395 itself. Only on the wires separately. 12v should be on pin 3, ground should be on pin 1, LIN bus is on pin 2. The problem with the wiring of the LIN bus line on the B8.0 is documented. That might be your issue, https://static.nhtsa.gov/odi/tsbs/20...28363-9999.pdf

The G395 is not on the engine harness, so it doesn't go through the 17-pins. It's on the engine bay harness, and is wired directly through the fender opening. https://www.audizine.com/forum/showt...1#post15076928

[fastboatster]

I didn't measure the G395 itself, I was measuring the resistance between pins 1 and 3 of its harness connector (ground vs 12 V, battery removed from the car)
I think what I was trying to say is that some ECM grounds are not connected to the engine or chassis directly, they go to the J519.
Thanks for the link, I did visually inspect the wiring going to that sensor, including the headlight area and the whole wiring harness going from there to the fender opening. Didn't find an issue there, my AC works, it's just that I noticed that I get an occasional implausible signal warning. I also forgot to mention that I checked other sensors which use the same voltage supply wire on the fuse block, like the air quality sensor at the HVAC air inlet box, and they all had the same resistance between the ground and power supply.
I'm trying to say this is probably an indicator of another issue. I.e., when the fuse for the voltage supply for G395 sensor is pulled, there's no longer any continuity between the terminal 1 and 3 of G395 wiring harness connector, same goes for the air quality sensor.
I think the issue is that there's continuity between the wire which supplies positive voltage for G395 and some other sensor to the fuse block. I'll take a picture and show what I mean.

[fastboatster]

Okay, posting some pics so it makes more sense.
First one is a terminal in the AC fuse holder in the driver's side fuse panel. This terminal is connected to the pin 3 of G395 sensor connector. No continuity between this terminal and any chassis grounds, and no continuity to pin 1 of G395 sensor connector (of course measured with that connector unplugged from the sensor).

Second - terminal in the same fuse holder, but this one is connected to the rest of the wiring. Measures about 20 Ohms to the ground on the strut tower.

Back side of the fuse holder:

This thick black wire is connected to the terminal from the picture above and also measures 20 Ohms to the ground. Even though it's black and not red like most of the positive wires would be, wiring diagram indicates this is not a ground wire.

[Smac770]

The supply wire from the term 15 relay to the panel C column black is a single 6.0 mm² black wire, as documented in the wiring diagrams. The fuse holder has an internal bus bar that distributes the term 15 to the supply side of all 16 fuse positions. So the 20 Ω measurement is from that probe contact point over all the fuse connected devices in parallel.

To assess that 20 Ω, you'd have to pull all the fuses and measure the resistance from the device side of each fuse slot to chassis ground. See who actually has a resistance value to chassis, see what devices are connected to that fuse. Fuse 6, e.g., runs headlamp devices on both sides.

Fuse 5 is the fuse to the G238. Fuse 12 is the fuse to the G395. Both of these devices ground through the wiring harness to the base of the left a-pillar. Both of these devices' pin 2 is the LIN bus pin, which splice together, and then run to the J519 16-pin pin 4. Neither device has any power or ground interaction with the J519. Implausible signal could be nothing more than flaky LIN communications, which is a known issue due to LIN bus line wire issues, as noted in the TSB. Could be a corrosion issue, could just be a splice issue, could be one of the devices flaking out and trashing the line signal.

[Smac770]

Audi 8K 8T fuse holder layouts 2.JPG

[fastboatster]

The supply wire from the term 15 relay to the panel C column black is a single 6.0 mm² black wire, as documented in the wiring diagrams. The fuse holder has an internal bus bar that distributes the term 15 to the supply side of all 16 fuse positions. So the 20 Ω measurement is from that probe contact point over all the fuse connected devices in parallel.

To assess that 20 Ω, you'd have to pull all the fuses and measure the resistance from the device side of each fuse slot to chassis ground. See who actually has a resistance value to chassis, see what devices are connected to that fuse. Fuse 6, e.g., runs headlamp devices on both sides.

Fuse 5 is the fuse to the G238. Fuse 12 is the fuse to the G395. Both of these devices ground through the wiring harness to the base of the left a-pillar. Both of these devices' pin 2 is the LIN bus pin, which splice together, and then run to the J519 16-pin pin 4. Neither device has any power or ground interaction with the J519. Implausible signal could be nothing more than flaky LIN communications, which is a known issue due to LIN bus line wire issues, as noted in the TSB. Could be a corrosion issue, could just be a splice issue, could be one of the devices flaking out and trashing the line signal.

Thanks a lot, Smac! it's a very good idea to check other devices connected to that 6mm^2 wire, you are right that the short might be located on the side of other devices. and thanks for telling me that this wire is coming from the terminal 15 relay, I can also check the resistance there. As for the sensor reading, I was thinking that this short might be causing some positive voltage to show up on the negative terminal of that sensor, effectively reducing the supply voltage to it and perhaps making it either not send or send an incorrect signal.
P.S. and thanks for the fuse diagram!

[fastboatster]

well, thanks to the fuse diagrams and ideas Smac provided, I think I was able to find the circuit where the short is. I didn't have to do a lot of resistance measurements, either. Once I pulled the fuse next to the ac sensor power supply, which is a heated washer jets fuse, I found these 22 Ohms and there's no more continuity between the T15 supply wire and the ground. And yes, I did replace the washer jets a while ago because the ones I had got clogged due to all the soil in the washer fluid reservoir, which I also removed and cleaned at that time. Will try to investigate this circuit more in the next few days. Are we really getting to the bottom of this issue? I guess I'll need to check what I'm getting on the ECM lambda sensors grounds with this fuse off and voltage on the cam adjuster solenoid PWM grounds.

[Smac770]

Well, the problem is the Z20 left headlamp washer heater and Z21 right headlamp washer heater are just passive heater grids. So you'll read a static resistance from the fuse to ground across those. I assume they are 44Ω each, as the two are in parallel. So as long as ignition is on (term 15 is active), the heaters are energized. That's a crazy 0.55A to be losing the entire time ignition is on, even when you're just in the garage doing some VCDS work.

[fastboatster]

Well, the problem is the Z20 left headlamp washer heater and Z21 right headlamp washer heater are just passive heater grids. So you'll read a static resistance from the fuse to ground across those. I assume they are 44Ω each, as the two are in parallel. So as long as ignition is on (term 15 is active), the heaters are energized. That's a crazy 0.55A to be losing the entire time ignition is on, even when you're just in the garage doing some VCDS work.

Hold on, I don't have headlamp washers, only windshield washers. I wonder what their actual resistance is, I might or might not have tossed the old jets. If their nominal resistance is 44 Ohms, that would be about 7 watts.
P.S. looks like Audi is using PTC (Positive Temperature Coefficient) heaters just like most of the cars do. These are supposed to have their resistance rise sharply at 32F when heating is not needed. 7 Watts of power draw for these at 70F seems like too much.

[Smac770]

If you were measuring Ω from the device side terminal of driver's end, column black, fuse 11 to chassis ground, the wiring diagram only documents the Z20/Z21 headlamp washer heaters attached to that fuse position, for B8.0. B8.5 has that fuse position for the lane change assist (side assist) radars, as the Z20/Z21 are driven directly by the J519.

My MY09 Prestige does not have headlamp washers. I don't know anything about the location or design of the heaters. It could be they are variable resistance heaters. The heated seats for example use a thermistor reading to tell the J519 how to vary the voltage to the heater grid; the thermistor is not inline with the heater grid. But if you didn't have, or have removed, the headlamp washers, then why is there a wire terminal on the device side of the fuse 11 position?

[Smac770]

Very odd. I went and looked, and I have a fuse 11, 5A. And it has a wire terminal on the device side. And I measure it at 43Ω to the big chassis bolt above the fuse holder. ...?

Ok, nevermind. "washer jet", but they mean the windshield washer jet, not the headlamp washer jet. What happens when the documentation fails to be complete for all objects. It was listed right next to the V11 headlamp washer pump, so I assumed they were related components.

So it's the heaters for the windshield washer jets mounted under the hood. But I do measure it a much more than yours, with the garage temp currently at 85°F.

[fastboatster]

Very odd. I went and looked, and I have a fuse 11, 5A. And it has a wire terminal on the device side. And I measure it at 43Ω to the big chassis bolt above the fuse holder. ...?

Ok, nevermind. "washer jet", but they mean the windshield washer jet, not the headlamp washer jet. What happens when the documentation fails to be complete for all objects. It was listed right next to the V11 headlamp washer pump, so I assumed they were related components.

So it's the heaters for the windshield washer jets mounted under the hood. But I do measure it a much more than yours, with the garage temp currently at 85°F.

thanks, appreciate that you went and measured it. 43 is not that far off from 22, the same order of magnitude, but not sure if that's significant for a particular circuit. afaik, that resistance should sharply increase with temp, but I don't know the specific characteristic curve. I'll remove the windshield washer jets tomorrow and inspect the wiring there. as I recall, these were really hard to remove at that time, could have damaged the wiring. I also need to trace how the ECM lambda grounds are connected to the body harness and potentially to J519, it is still possible the real issue is there...

[Smac770]

You talk about the lambda sensors, that has me wondering why.

So to start, we have LSU 4.9 wide band lambda sensors on the pre-cat and standard jump sensors on the post-cat. The pre-cat are 6-wire, with 4 for the sensor and 2 for the heater. The post-cat are 4-wire, with 2 for the sensor and 2 for the heater. All the wires except the heater + are connected directly to the J623. The heater + is connected directly to a fuse in the ECM box (10 for the pre-cat, 9 for the post-cat). The J519 is not involved.

J623 = ECM, engine control module, in the ECM box
J519 = BCM, body control module, under the dash

G39 pin > wire > J623 pin
1 > gray > 82
2 > green > 61
4 > violet > 83
6 > red > 84
3 > brown/black > 73 (this is the ECM controlled ground line for the heater)
5 > green/yellow > fuse 10 (this is the J757 relay switched 12v for the heater)

G108 pin > wire > J623 T94 pin
1 > brown/red > 81
2 > green/red > 59
4 > red/violet > 60
6 > brown/yellow > 62
3 > black/green > 51 (this is the ECM controlled ground line for the heater)
5 > green/yellow > fuse 10 (this is the J757 relay switched 12v for the heater)

These are different from the ones for the EA888, which has the heater on the expected pins 3 and 4. Going by function in the diagrams:

LSU 4.9 >> EA888 6-pin > EA837 6-pin
pump current IP >> 1 > 1
virtual ground VN >> 2 > 6
heater - Uh- >> 3 > 3
heater + Uh+ >> 4 > 5
trim resister IA >> 5 > 4
nernst voltage UN >> 6 > 2

You can test resistance along the wire from the 6-pin plug pin to the 94-pin plug pin, but you can't test the resistance across the various sensor pins of the lambda for any useful purpose. The quoted spec of 300 Ω for the nerst cell is an AC impedance, between 1 kHz and 4 kHz. You can test DC resistance for the heater pins; should be about 3 Ω.

So not sure what all is the interest in the lambda sensors re harness grounding. They don't cross paths, except on the other side of the J623.

[fastboatster]

I backprobed lambda sensor virtual grounds at the ECM connector, K62 and K84 ("Virtual ground LS upstream 2" and "Virtual ground LS upstream 1", respectively) and measured voltage across these 2 grounds and body ground, found that there's 2 Volts between each of those and body ground. I.e., I didn't measure voltage between "6 and 2", that would be a sensor voltage output.

[Smac770]

Yeah, but you can't assume anything about the chassis ground on the battery side of the J623 vs the sensor ground on the lambda side of the J623. There's no reason to assume these can be electrically related unless you have the J623 circuit schematics and see the J623 is connecting chassis ground to the pins 62 and 84. If in fact chassis ground is routed to 62 and 84 and you're measuring a voltage difference, then the issue is more likely to be in the J623 itself than any wiring issue.

I wouldn't conclude a voltage reading between 62/84 and 1/2/4 to be indicative of an issue. If there is an issue, the wiring is super direct to asses, the rest is in the sensor itself.

[fastboatster]

Yeah, but you can't assume anything about the chassis ground on the battery side of the J623 vs the sensor ground on the lambda side of the J623. There's no reason to assume these can be electrically related unless you have the J623 circuit schematics and see the J623 is connecting chassis ground to the pins 62 and 84. If in fact chassis ground is routed to 62 and 84 and you're measuring a voltage difference, then the issue is more likely to be in the J623 itself than any wiring issue.

I wouldn't conclude a voltage reading between 62/84 and 1/2/4 to be indicative of an issue. If there is an issue, the wiring is super direct to asses, the rest is in the sensor itself.

hmm, all of the grounds eventually go to the chassis, the car is made out of relatively well conducting material. I doubt that there's much resistance between, say, strut tower ground and a ground on the A pillar. I did try this measurement (ECM lambda ground vs body ground) with 2 different ECMs, one original and another one with some eBay ECM (with removed immobilizer) and it's the same result.
P.S. I think that ECM is getting 62/84 ground somewhere from the J519, not from the battery ground. It's definitely the case for some other sensor grounds, otherwise hard to explain the intake manifold flap sensor overvoltage code when F22 switch wires only connected to J519 are shorted.

[Smac770]

The J623 has three of its own grounds to the vehicle. It needs nothing ground wise from the J519, which has its own completely independent grounds to the chassis. The J623 grounds are part of the engine harness, and ground to the ground post in the plenum chamber left (under the washer fluid filler cap; next to the ECM box). The J519 grounds are part of the interior harness, and ground to the base of the left a-pillar. That said, a lot of stuff the J519 powers also grounds their own way through the interior harness. Such as the headlights, which ground to the base of each a-pillar. So the J519 itself has a ground path to the left a-pillar, and the J519 sends power to the left headlamp which has a ground path to the left a-pillar, but it's not the same ground wire path.

intake manifold runner position sensor, G336 bank 1 and G512 bank 2. These six wires pass through the 14-pin. They get 5V from the ECM, ground from the ECM, and the signal lines. They appear to be basic potentiometers. So pin 2 is just going to be a voltage divider value between 5V on pin 1 and ground on pin 3. The F22 sense line comes from the J519, but the F22 ground line goes through the engine harness to the plenum chamber left ground post.


>>>> F22 is wired completely different for B8.0 CCBA vs B8.5 CGXC/CTUB.

For B8.5, F22 sense wire comes from the J623 ECM, and the ground wire is connected to the ECM sensor grounds, which is back to the ECM, not to the chassis. What's in the car currently?

engine - B8.0 CCBA, B8.5 CGXC, or B8.5 CTUB?
engine harness - B8.0 CCBA, B8.5 CGXC, or B8.5 CTUB?
ECM - B8.0 CCBA, B8.5 CGXC, or B8.5 CTUB?

[fastboatster]

I have B8.5 CGXC with B8.0 CCBA harness and ECMs. According to my wiring diagrams, F22 is connected to J519 on B8s like you said.
P.S. if there's really no ground supply from J519 to the ECM, I wonder if the voltage I saw on lambda sensor grounds at the ECM connector is due to some sensor supply voltage being too high. Aren't some 5V sensor voltage pins connected to J519?

[Smac770]

I'm not aware of any 5V on the J519 BCM. The 5V references in the wiring diagrams are on the J623.

For the CCBA harness, that's "D141", from J623 T60/35, and "D174", from J623 T94/63. D141 is the harness connection to which the IM flap angle sensors are "powered". They are just passive potentiometers, so quite different from the integrated circuit sensors such as the lambdas and LIN devices (G395, G238, etc).

You need to go back to the live error state of this "intake manifold flap sensor overvoltage code" and measure the voltage at the pins at the sensors, or maybe more easily, the pins at the T14g plug (not sure where that is on a 3.0T). Keep in mind that there's no requirement for the ECM sensor ground to read 0v to chassis ground. It only has to read 5V from "D141" to "132" (the sensor ground line from T94/39). Specifically what P code did you have?

[fastboatster]

I'm not aware of any 5V on the J519 BCM. The 5V references in the wiring diagrams are on the J623.

For the CCBA harness, that's "D141", from J623 T60/35, and "D174", from J623 T94/63. D141 is the harness connection to which the IM flap angle sensors are "powered". They are just passive potentiometers, so quite different from the integrated circuit sensors such as the lambdas and LIN devices (G395, G238, etc).

You need to go back to the live error state of this "intake manifold flap sensor overvoltage code" and measure the voltage at the pins at the sensors, or maybe more easily, the pins at the T14g plug (not sure where that is on a 3.0T). Keep in mind that there's no requirement for the ECM sensor ground to read 0v to chassis ground. It only has to read 5V from "D141" to "132" (the sensor ground line from T94/39). Specifically what P code did you have?

It had "P201000 - Intake Manifold Runner Bank 1 Control Circuit High code" after I replaced the F22 switch. B8 and B8.5s have different F22 switches, I replaced a pink B8.5 switch with a gray B8 F22 switch. Wiring at that connector had some exposed copper and 2 wires to that switch got twisted together creating a short, easy to do in a spot with tight access like that. I had P201000 right after that, and it continued to show up every time the flap needed to open. I even applied vacuum to both flaps together and also separately, and measured voltage output and the affected bank clearly had a larger reading when fully open. The fault disappeared instantly when it was discovered that bare wire sections were twisted together and insulation was repaired. These 2 F22 swithc wires don't seem to be directly connected to the ECM, one wire is connected straight to J519, and another to some ground. I think it makes sense to suggest that F22 wiring switch short at the F22 switch connector was a cause of ECM's P201000 code, not a coincidence at all. Interestingly, it affected only one bank. I.e., it looks like shorted wiring on J519 is affecting J623. I am not sure what's supposed to happen in the case like that, "healthy" J519 probably should recognize the short and it shouldn't affect other circuits.
Speaking of no requirement for the ECM sensor grounds to read 0v to chassis ground, I have backprobed ALL the ECM grounds on both connectors, and ALL except for the upstream O2 sensors were reading very close to 0 to the chassis ground, and that included downstream O2 sensors. I find this very unusual.
I also went and checked windshield washer jets, each measured about 40 Ohms, so no wiring problem there since that would amount to 20ish Ohms in parallel. 20-22 Ohms total is half of what you got, but it looks like 2009 has a different heated washer nozzle p/n, so probably resistance difference is not an indicator. If these jets were bad, I wouldn't think that both had almost the same resistance.
I wonder what kind of inputs ECM is getting from the J519, there might be some unusually high voltages there, something like "ghost" clutch position sensor signal or else. It looks like we have established that ECM is not getting any grounds via J519, and it's not getting 5V voltage from there, either. I think this might be relevant to this discussion - when I connect the negative battery cable back, I typically get "function limitation due to overvoltage" codes in many control units like doors etc which don't show up after they are cleared and everything works afterwards.
P.S. I think I might need to think of this in terms of current, not voltage. When the current is flowing from some positive ECM pin via some sensor to the ground, the voltage at the ground pin is the resistance between that pin and the ground. So it might be that it's a bad ground issue here, at least with these 2 lambda sensors. I wonder if the current is "flowing" to the ground points on the engine heads.

[Smac770]

Oh, control circuit, that's completely different than the sensor.

The F22 is the same for B8.0 and B8.5. It was 06E919081C, gray, through Jan '14. Then it was changed to 06E919081G, violet. The gray remains the R&R for the 3.2L CAL, but the violet is the R&R for the 3.0T non-CRE. They are not identical trigger spec. Gray is 2.5-3.2 bar; violet is 2.3-2.8 bar. But electrically, they are interchangeable. The change date seems to relate to a TSB on the subject: https://static.nhtsa.gov/odi/tsbs/20...65437-2280.pdf What's wrong with the gray, no idea.

Apparently, 06E919081D is also a 2-pin gray, but that's a F378 switch (0.75-1.05 bar) for the CRE engine.

Ok, so the visual confirmation is the white/gray from the J519 and the brown to the engine harness ground circuit (131) were shorted together. If any damage was done, I'd expect it to be to the J519 circuit for the F22.


So to the flap control solenoid, the N316. There's a flap position sensor on each bank, one for each flap runner. But there's just one activation solenoid for passing the vacuum to the actuators. N316 is powered direct by 12v from the fuse 5 in the ECM box, and selectively grounded by the ECM. Violet/white wire from N316 pin 1 to J623 T60/36.

But the question becomes what's the actual problem with the flap activation.

P2010
Intake Manifold Runner Control Circuit High Bank 1
Intake Manifold Runner Control Circuit / Shorted to B+ Bank 1
• signal current > X amps for at least 2 seconds

Interestingly, MY10 has P2010 triggered by > 1 amp, but MY11 and MY12 are > 2 amp. Guess they were getting too many false concerns.

But so how does P2010 occur? The ECM grounds T60/36 and sees more than 1 amp of current flow.

If you measure the resistance reading across the N316 solenoid from pin 2 to pin 1, what does it read? If there's always 12v on pin 2, then as soon as the ECM grounds pin 1, V/R = I is going to happen.


Wonder if that violet/white wire from the J623 to the N316 is shorted in the harness to the gray/white from the J519 to the F22.

[fastboatster]

I think you are looking to much into P2010. It is no longer present, I have told you what I had to do to resolve it. I think you are misinterpreting the "Control Circuit" part, it is not related to the solenoid. There's only one solenoid for both banks, so this code couldn't be bank-specific if it really was about the solenoid. It is about the signal from the flap, I measured flap sensors' outputs when applying vacuum to the flaps, the flap with the fault had higher reading (about 1V when fully open) than the side without. I don't think this code has anything to do with solenoid at all, I think it's because the reference voltage to that flap was higher than normal.

[Smac770]

I don't think I'm misunderstanding P2010 at all. https://www.audizine.com/forum/showt...1#post14651789

If there's only one, then "bank 1" is going to be the generic code text. There's not going to be a "no bank specified" version of the P2008-P2010 (Intake Manifold Runner Control Circuit, bank 1) and P2011-P2013 (Intake Manifold Runner Control Circuit, bank 2) P codes. P2011-P2013 are not in the 3.0T documentation because there is only one. And as I apparently copied from the CTUB document, they did clean up the documentation text for the P2008-P2010 codes. If it had been referring to the sensor, there would have to be bank 1 and bank 2 codes. I'm sure you measured stuff on the sensor side, but the P code was never talking about the sensor.

But if it's fixed, then what is the actual live issue right now? It's a winding history, and it's hard to remember what's going on when I come back across this thread each time beyond what I read in the posts since my last post.

[fastboatster]

yes, very winded story. Right now, I am getting codes P052A00 and sometimes P052C00 at cold start. This happens with 8 Ohm cam solenoids, doesn't happen with 7 Ohm solenoids. 7 and 8 are both in spec for these solenoids. I also observed the same when the CCBA engine was installed. Like I said before, I see a voltage of 4V vs chassis on the PWM grounds of these solenoids (plug disconnected from the solenoid, everything on, engine not running), and about 7V DC across the solenoid plugs. I can't just keep 7 Ohm solenoids installed, because this is bandaid, plus the ones with 7 Ohm I got happen to be from the CCBA and although these physically fit, but can't be bolted to the engine.
Other things are engine vibration at idle, and fouling spark plugs, while fuel trims are all less than 5% (combined LTFT + STFT) (smoke tested the crankcase and the intake, no observable vacuum leaks there). Very similar to what was happening with CCBA engine, where I also measured exhaust back pressure to rule out the cats.

[Smac770]

MY10 CCBA:

P052A
Cold Start "A" Camshaft Position Timing Over-Advanced, Bank 1
Intake (A) Camshaft Position Actuator Circuit / (Bank 1)

P052C
Cold Start "A" Camshaft Position Timing Over-Advanced, Bank 2
Intake (A) Camshaft Position Actuator Circuit / (Bank 2)

• adjustment angle difference > 10° CA; 2 second window
• number of checks 2

• engine speed > 700
• "modeled oil temperature (no map. just bottom and top limit)" -10 … 130°
• delta set point 0° CA
• than wait 0 Sec

The 3.0T dropped the VVT on the exhaust cam "B". Thus only P codes for the intake cam "A" are defined, and you're getting both.

---------------

So starting from the actual P codes themselves, have you observed this issue in the measuring values? Especially since you say you can A/B test two different solenoids to have/not have the issue.

Engine speed
Camshaft adjustment: inlet phase: bank 1
Camshaft adjustment: inlet phase: bank 2
Camshaft adjustment: inlet: bank 1/2: specified
Camshaft adjustment: inlet: bank 1: actual
Camshaft adjustment: inlet: bank 1: duty cycle
Camshaft adjustment: inlet: bank 2: actual
Camshaft adjustment: inlet: bank 2: duty cycle

If you log those (always group UDS or the sample rate is worthless) on cold start with the two different solenoids, what is the actual difference in the data which might be setting off the P code. When does the issue occur, for how long, and how significantly (not just is it more than 10, but how much more).

I don't have a 3.0T to explore values and see what others might be interestingly relevant. The following labels are curious, for example:
PSN_EDGE_1_AD_CAM_IN_1
PSN_EDGE_1_AD_CAM_IN_2
PSN_EDGE_2_AD_CAM_IN_1
PSN_EDGE_2_AD_CAM_IN_2

I couldn't tell if any of the voltage values seemed relevant to say an adaptation value for the camshaft adjusters. I have a Bosch doc for trying to decipher some of the cryptics, but EA837 uses Simos.

---------------

So the N205 for bank 1 intake cam and the N208 for bank 2 intake cam. Electrically, these are simple on/off solenoids. The only test spec for them is 5-20 Ω (±3 Ω @ 20°C) measured between pin 1 and pin 2. On the EA888, the solenoid and the control valve are separate objects. On the EA837, the solenoid and (oil flow) control valve are a single joined object.

The Ω test spec for the solenoids is the same in both the CCBA and the CGXC/CTUB workshop manuals. So the Ω difference is not the item of interest between the solenoids.

N205/N208 for CCB is 06E109257L. The 3.2L CAL uses the same (though four of them).
For the CGX/CTU, it is 06E109257N, later replaced by S, then T, and finally AC. The EA837evo (CRE) uses the same as CGX/CTU.

The question then is what changed, and why does the later change port back to the earlier implementations? Is it a physical change matching to some physical adjustment of the engine?

So 7Ω vs 8Ω is not significant. What is significant is the actual p/n. Which p/n works fine and which p/n does not? Because it has to be remembered that the CAL & CCB use a different adjuster unit than the CGX & CTU. So the CAL & CCB use one solenoid+control valve <> adjuster unit part pairing, and the CGX & CTU use a different solenoid+control valve <> adjuster unit part pairing.

---------------

The solenoid duty cycle can be seen in the measuring values. I can't find a reference for what the PWM frequency is.

pin 1 - 12v from fuse
pin 2 - ECM controlled ground

That you see 12v going into pin 1, 7v drop from pin 1 to pin 2, then 4v drop from pin 2 to ECM would seem odd, unless the ECM is setting a 4V basis on the ground line to minimize current draw through the solenoid. There might be some manner of adaptation for this base voltage? Do you see this same electrical foot print with either version of solenoid?

"I also observed the same when the CCBA engine was installed"? When you talk about 7Ω and 8Ω solenoids, are you talking about different p/n revs, or different suppliers?

To truly isolate the wiring harness as maybe having a chafing issue and the brown/x to 54 or blue/y to 39 (the stripe color is different for B8.0 vs B8.5, but the rest is the same) having some shorting issue, you'd want to run a clean wire between the two points and see what happens. That one rev works and one doesn't, seems to be more about the solenoids.

The problem is the physical and electrical are linked on the EA837 versions. A CGX/CTU cylinder head appears to require the AC valve, but maybe the CCB ECM isn't designed sufficiently for it electrically. But that's the question, is that the issue at hand. Or is there an issue in the harness instigating the variance.

[fastboatster]

one quick note - I have multiple CCBA solenoids, most of these is 7 Ohm, but there's one with 8. And that one doesn't work, either. So 7 vs 8 Ohm seems to be relevant.

[Smac770]

Then run fresh wires and see what happens.