ANOTHER AUDI NOT RUNNING....Fuel pump not getting power

[Jdraco592]

Okayy

For the last couple of years, I've had this sputter in my 2014 Allroad 2.0Tsfi. I originally thought it was a bad fuel module, after R&R that was determined to not be the problem. Within the last year after chasing countless fault codes, I have replaced: Cam follower, High-pressure fuel pump, spark plugs, and coil packs. Last week the car decided to stop running entirely, I brought it to the dealership where the Fault code P2636 popped up. Along with low fuel pressure, the dealership diagnosed the issue as a faulty low-pressure fuel pump. I just replaced the low-pressure fuel pump and the car still doesn't run.

Here is what I know so far, I have 12v to the fuse for the fuel pump. I have 1 volt at the pump, when I open the car door I can hear the in-tank pump try to prime but it sounded labored.
I still have one code remaining P0116 (engine coolant sensor temp) , Just thought i'd include it....

I'd like to know,

1) Does anyone have a wiring diagram for the fuel system to trace out issues.
2) Do I need to force a prime after changing a fuel pump?
3) Where is the Crankshaft position sensor on the 2.0 B8?
4) Which wires do what in the 4-prongs connecting to the fuel pump? (black, blue, green, yellow)?

Thanks in advance for all your assistance!

[JLAllroad]

Okayy

For the last couple of years, I've had this sputter in my 2014 Allroad 2.0Tsfi. I originally thought it was a bad fuel module, after R&R that was determined to not be the problem. Within the last year after chasing countless fault codes, I have replaced: Cam follower, High-pressure fuel pump, spark plugs, and coil packs. Last week the car decided to stop running entirely, I brought it to the dealership where the Fault code P2636 popped up. Along with low fuel pressure, the dealership diagnosed the issue as a faulty low-pressure fuel pump. I just replaced the low-pressure fuel pump and the car still doesn't run.

Here is what I know so far, I have 12v to the fuse for the fuel pump. I have 1 volt at the pump, when I open the car door I can hear the in-tank pump try to prime but it sounded labored.
I still have one code remaining P0116 (engine coolant sensor temp) , Just thought i'd include it....

I'd like to know,

1) Does anyone have a wiring diagram for the fuel system to trace out issues.
2) Do I need to force a prime after changing a fuel pump?
3) Where is the Crankshaft position sensor on the 2.0 B8?
4) Which wires do what in the 4-prongs connecting to the fuel pump? (black, blue, green, yellow)?

Thanks in advance for all your assistance!

Did you already replace the controller? What brand pump was used to replace? What shop?


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[Jdraco592]

The controller was replaced in July, I'm not sure about the brand of fuel pump but it is identical to the OEM.

[JLAllroad]

The controller was replaced in July, I'm not sure about the brand of fuel pump but it is identical to the OEM.

Brand does matter, did you replace the filter as well? FP regulator is a component of the filter.


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[Jdraco592]

Yes, the filter and entire in tank fuel assembly was replaced. What are you thinking?

[jjvwg]

I would replace your coolant temp sensor before you continue to troubleshoot the fueling situation as the ECU requires a good temp reading to control fueling to run properly. This can definitely cause a no start situation. Unfortunately on newer cars with a fuel pump controller and fuel pump being driven by PWM signals it’s hard to troubleshoot with a basic electrical meter. What brand controller did you put in in July? For something like that I’d recommend the OEM pierburg unit. If the CTS doesn’t resolve your no start you could also check to make sure your fuel pump relay is working correctly.


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[JLAllroad]

I would replace your coolant temp sensor before you continue to troubleshoot the fueling situation as the ECU requires a good temp reading to control fueling to run properly. This can definitely cause a no start situation. Unfortunately on newer cars with a fuel pump controller and fuel pump being driven by PWM signals it’s hard to troubleshoot with a basic electrical meter. What brand controller did you put in in July? For something like that I’d recommend the OEM pierburg unit. If the CTS doesn’t resolve your no start you could also check to make sure your fuel pump relay is working correctly.


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I started (and drove) this a bit the other day. Only a few issues, but nothing that would keep it from doing either.

Said another way, these will start and run with any number of issues as long as its not internally broken, or affect air, fuel, spark.
IMG_8769.jpg


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[RPMtech147]

Okayy


1) Does anyone have a wiring diagram for the fuel system to trace out issues.
2) Do I need to force a prime after changing a fuel pump?
3) Where is the Crankshaft position sensor on the 2.0 B8?
4) Which wires do what in the 4-prongs connecting to the fuel pump? (black, blue, green, yellow)?

1.)See below
2.)No you aren't required to force prime with a scan tool. Just key-on, key-off a few times. It might be stumbly for a few seconds on first start till it clears the air out of the system.
3.) It should be on the drivers side of the engine block, toward the back, low, close to the transmission.
4.)See below




J538- Pump control module
G6 - Fuel pump
Pin 4 at the pump is ground, the brown wire.
The other 3 lines I believe are the "control wires", go directly into the pump motor itself. If I recall, it's a "3 Phase DC pump" with PWM control(Hence the 4 wires), so you can't just give it 12V like a conventional pump.


I'd get your test light/DVOM and make sure that ground is good.

Also, check the pins inside the connector. Make sure they're not spread open, perhaps from someone jamming a probe into it.



(For the electrical gurus, I don't know how 3-phase DC is even a thing...That's for AC current..sorry, getting off topic.)





During cranking or running, you should see about 6 volts on each of the 3 control wires, that gives you a little bit of data. *You really need a lab scope to see what's going on but I think you can fix it without one.

I doubt the temp sensor is causing the issue.
I suspect the pump was installed wrong or you have a faulty new pump. Have you verified fuel pressure?
If you hear the pump running that somewhat rules out electrical, but still need to check connector and ground.

Also, the wiring diagram colors I show are different than what you're saying. Are you talking about the wiring on the pump itself, that go inside the tank?

[jjvwg]

I started (and drove) this a bit the other day. Only a few issues, but nothing that would keep it from doing either.

Said another way, these will start and run with any number of issues as long as its not internally broken, or affect air, fuel, spark.
IMG_8769.jpg


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Not sure what your getting at here, your last sentence pretty much just reaffirmed what I said.


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[JLAllroad]

Not sure what your getting at here, your last sentence pretty much just reaffirmed what I said.


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I’m saying that the coolant temp sensor isn’t going to stand in the way of this starting.


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[Smac770]

B8.0 uses a single-phase 2-wire Bosch pump.
B8.5 uses a three-phase 4-wire VDO (Continental) pump.

You should be able to run an output test to activate the pump via a scan tool (B8.0 used direct 12v application because it was a single-phase pump; can't do that with the B8.5; have to use the scan tool to feed a PWM duty cycle from the ECM to the FP controller, which will then modulate the three phases to pump). This should allow you to validate the fuel pressure from the in-tank pump as well as the flow volume (procedures documented in the fuel supply system workshop manual).

If you validate the fuel pressure and fuel flow from the in-tank pump using the scan tool test, then that's not your problem.

[Jdraco592]

Hey guys,

I appreciate your responses, I'm starting to tinker with the car right now. In the meantime, I thought you should know that I tend to buy the cheapest parts possible that are guaranteed to fit my vehicle. I will put the link to the parts below since they do not have any brand names on the parts. I have a 3-phase fuel pump, not a conventional 12v. I guess that means I have a B8.5.

Since I have had the Coolant temp issue for the last couple of months, I'm going to agree and say that is not my starting issue.
**** to verify that the motor is mechanically sound and it wasn't something internal, I sprayed starting fluid into the intake. The engine runs perfectly so, we are dealing with some electrical gremlin.

I would like to know where the relays for the fuel system. I did not see any under the hood, thought it would be easier to ask than dick around.

Also, my fuel pump# is: 8K0-919-051-AN, the pump I got says it replaces part numbers 8K0919051AJ, 8K0919051AS. So I ask.... What makes the difference between the CPMB and CAED Engines? Could this just be the wrong fuel pump, despite the fact that they are identical?


https://a-premium.com/product/Fuel-P...-A4-4FbAtKUhwK. - FUEL PUMP ASSEMBLY

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 - FUEL CONTROL MODULE

[JLAllroad]

Hey guys,

I appreciate your responses, I'm starting to tinker with the car right now. In the meantime, I thought you should know that I tend to buy the cheapest parts possible that are guaranteed to fit my vehicle. I will put the link to the parts below since they do not have any brand names on the parts. I have a 3-phase fuel pump, not a conventional 12v. I guess that means I have a B8.5.

Since I have had the Coolant temp issue for the last couple of months, I'm going to agree and say that is not my starting issue.
**** to verify that the motor is mechanically sound and it wasn't something internal, I sprayed starting fluid into the intake. The engine runs perfectly so, we are dealing with some electrical gremlin.

I would like to know where the relays for the fuel system. I did not see any under the hood, thought it would be easier to ask than dick around.

Also, my fuel pump# is: 8K0-919-051-AN, the pump I got says it replaces part numbers 8K0919051AJ, 8K0919051AS. So I ask.... What makes the difference between the CPMB and CAED Engines? Could this just be the wrong fuel pump, despite the fact that they are identical?


https://a-premium.com/product/Fuel-P...-A4-4FbAtKUhwK. - FUEL PUMP ASSEMBLY

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 - FUEL CONTROL MODULE

Sigh, cheap will cost you in the long run.

I’m sure [mention]Smac770 [/mention] will correct me if I’m wrong, but, CAED is a manual paired motor, more based on the B8 architecture and all US Allroads are B8.5 flex fuel, which the CAED is not.

I’m ok saving money but all 2014 2.0ts are not the same, nor are their fueling components. There is definitely money to be saved, Audi vs OE manufacturers, and there’s times where the aftermarket is perfectly fine if not better, but, some of the issues that you are experiencing may be of your own doing.


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[Jdraco592]

1.)See below
2.)No you aren't required to force prime with a scan tool. Just key-on, key-off a few times. It might be stumbly for a few seconds on first start till it clears the air out of the system.
3.) It should be on the drivers side of the engine block, toward the back, low, close to the transmission.
4.)See below




J538- Pump control module
G6 - Fuel pump
Pin 4 at the pump is ground, the brown wire.
The other 3 lines I believe are the "control wires", go directly into the pump motor itself. If I recall, it's a "3 Phase DC pump" with PWM control(Hence the 4 wires), so you can't just give it 12V like a conventional pump.


I'd get your test light/DVOM and make sure that ground is good.

Also, check the pins inside the connector. Make sure they're not spread open, perhaps from someone jamming a probe into it.



(For the electrical gurus, I don't know how 3-phase DC is even a thing...That's for AC current..sorry, getting off topic.)





During cranking or running, you should see about 6 volts on each of the 3 control wires, that gives you a little bit of data. *You really need a lab scope to see what's going on but I think you can fix it without one.

I doubt the temp sensor is causing the issue.
I suspect the pump was installed wrong or you have a faulty new pump. Have you verified fuel pressure?
If you hear the pump running that somewhat rules out electrical, but still need to check connector and ground.

Also, the wiring diagram colors I show are different than what you're saying. Are you talking about the wiring on the pump itself, that go inside the tank?

Sigh, cheap will cost you in the long run.

I’m sure [mention]Smac770 [/mention] will correct me if I’m wrong, but, CAED is a manual paired motor, more based on the B8 architecture and all US Allroads are B8.5 flex fuel, which the CAED is not.

I’m ok saving money but all 2014 2.0ts are not the same, nor are their fueling components. There is definitely money to be saved, Audi vs OE manufacturers, and there’s times where the aftermarket is perfectly fine if not better, but, some of the issues that you are experiencing may be of your own doing.


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I'm at a crossroads then, I'd hate to buy the proper fuel pump and module ($1000 total) before knowing the true nature of the problem and having the new parts not fix the root cause. Since you're in Denver, can you recommend any good shops that can button this up? The dealer wanted an arm and a leg to fix this which is why I brought the car back to my house to repair myself. The weird thing is, after I put in the new fuel pump the Allroad ran fine for 3 minutes, then died. I'm wondering why it would run and then die again. Also, what is a "manual paired motor"?

[Smac770]

You were already committed to being a B8.5 as soon as you said allroad. US A4 is B8.0 for MY09-MY12 (except MY09 A4 cabriolet is B7) and B8.5 for MY13-MY16. The B8.0 wagon in the US was the avant; the B8.5 wagon in the US was the allroad.

CAE is the EA888 Gen2 longitudinal motor for E0-E10 for US emissions (CDN for EU emissions).
CPM is the EA888 Gen2 longitudinal motor for E0-E85 for US emissions (CFK for EU emissions).

So they're essentially the same motor, and the underlying fuel system is the same architecture. The E85 vehicles just have different fuel pump and injectors and some other changes for the higher flow volume and aggressive corrosiveness of E85. See SSP 439.

All US B8 avants are B8.0 with the CAEB engine and ZF automatic (6HP28AF for MY09-MY10; 8HP55A for MY11-MY12).
All US B8 allroads are B8.5 with the CPMA (208bhp, MY13) / CPMB (217bhp, MY14-MY16) engine and ZF automatic (8HP55A, MY13-MY16).

All B8.5 manuals and CVTs have the CAE motor. Most B8.5 automatics have the CPM motor, but a MY13 automatic with the CAE motor would not surprise me. As such, I'd expect there to be many more B8.5 CPM engines than B8.5 CAE engines in the US market.


What are you using as a scan tool?


The in-tank fuel pump is 8K0 919 051 xx, where xx is:
AD > AH > dropped : E10 pump for 9M0
AE > AJ > AS : E10 pump for 9M9
AL > AM > AN : E85 pump

So the two in bold are what you buy for R&R purposes these days, AJ for CAE and AN for CPM. I point out the 9M0/9M9 thing because all US are 9M0, but the 9M9 pump has two open ports. So if you replace your factory pump with an AJ, you need cap 8R0 201 263 A to plug the port to the fuel driven aux coolant heater (which you won't have) or you'll have fuel everywhere. E85 versions should only have a single open port, I speculate. No reason to not visually confirm yourself though.


An AJ pump would probably be just fine in a CPM vehicle so long as you stick to E10 fuel. No idea how long it will last with E85 fuel.

Wow, those have gotten really expensive. But I have little faith in a sub $100 fuel pump, at least over the long term. You have the two tests defined to validate the pump operation. Perform them or not.


The pump controller doesn't care about E10 vs E85. It cares about EU vs US. 4G0 906 093 G > J (G, later replaced by J) for NAR (US/Canada) spec, 4G0 906 093 F > H for RoW (not US/Canada) spec. Not sure what's different, probably some kind of locking tab or such due to CARB (ie, why we have differently keyed hoses for the PCV, because CARB said it needs to be failsafe that hoses can't be installed backwards, etc).

[JLAllroad]

I'm at a crossroads then, I'd hate to buy the proper fuel pump and module ($1000 total) before knowing the true nature of the problem and having the new parts not fix the root cause. Since you're in Denver, can you recommend any good shops that can button this up? The dealer wanted an arm and a leg to fix this which is why I brought the car back to my house to repair myself. The weird thing is, after I put in the new fuel pump the Allroad ran fine for 3 minutes, then died. I'm wondering why it would run and then die again. Also, what is a "manual paired motor"?

Hardey's MotorWerks
(303) 840-7664
https://maps.app.goo.gl/xs69khcmBor9NUXp6?g_st=ic

Most CAEDs are paired with a manual transmission. I’m guessing with the low “take rate”, 1% or less? Audi didn’t want to go through the hassle of complete recertification.


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[RPMtech147]

https://a-premium.com/product/Fuel-P...-A4-4FbAtKUhwK. - FUEL PUMP ASSEMBLY

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 - FUEL CONTROL MODULE

Oof. I've got a B6 A4 in my stall right now that was towed in because the client installed an Amazon fuel pump. He said it lasted 2 days.

There are aftermarket brands that work just fine, but the no-name garbage they sell on Amazon/Ebay etc will cost you a lot more in the long run.

[Shane Horning]

Have you tried replacing the rail pressure sensor?

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[Jdraco592]

1.)See below
2.)No you aren't required to force prime with a scan tool. Just key-on, key-off a few times. It might be stumbly for a few seconds on first start till it clears the air out of the system.
3.) It should be on the drivers side of the engine block, toward the back, low, close to the transmission.
4.)See below




J538- Pump control module
G6 - Fuel pump
Pin 4 at the pump is ground, the brown wire.
The other 3 lines I believe are the "control wires", go directly into the pump motor itself. If I recall, it's a "3 Phase DC pump" with PWM control(Hence the 4 wires), so you can't just give it 12V like a conventional pump.


I'd get your test light/DVOM and make sure that ground is good.

Also, check the pins inside the connector. Make sure they're not spread open, perhaps from someone jamming a probe into it.



(For the electrical gurus, I don't know how 3-phase DC is even a thing...That's for AC current..sorry, getting off topic.)





During cranking or running, you should see about 6 volts on each of the 3 control wires, that gives you a little bit of data. *You really need a lab scope to see what's going on but I think you can fix it without one.

I doubt the temp sensor is causing the issue.
I suspect the pump was installed wrong or you have a faulty new pump. Have you verified fuel pressure?
If you hear the pump running that somewhat rules out electrical, but still need to check connector and ground.

Also, the wiring diagram colors I show are different than what you're saying. Are you talking about the wiring on the pump itself, that go inside the tank?

Have you tried replacing the rail pressure sensor?

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No need, Tested it and verified with a scan tool. The sensor works as intended.

[Jdraco592]

***** FIXED ********


Fuel Module came in this morning, Swapped it and she fired right up. After testing wires last night I could see voltage going into the module but no voltage or Hz would come out. I am keeping the $70 dollar fuel pump in the car for the time being (I never run E85), I will keep my original just in case there is a problem since all my fuel pressures are back to their normal operating ranges. Thank you for everyone's help!!

[RPMtech147]

That's a W. Nice job, OP.

[Jdraco592]

Until I took it for the test drive....she overheated so ill be checking the thermostat tomorrow when the tow truck brings it home. 😂
Is there another temp sensor that manages the electric radiator fans? They keep running regardless of temp, even before all of this...

[Smac770]

If they're always running, more likely an issue with the fan controller. The fan controller is not a passive reactive device, it's actively controlled by the ECM. So either the ECM is telling the fans to run all the time, or the fan controller has an electrical fault. It's easy enough to check the fan activation % in the ECM measuring values, if you have VCDS or such.

[RPMtech147]

Until I took it for the test drive....she overheated so ill be checking the thermostat tomorrow when the tow truck brings it home. 😂
Is there another temp sensor that manages the electric radiator fans? They keep running regardless of temp, even before all of this...

If the coolant temp sensor OR the Ambient air temp sensor are unplugged/faulty, the fans go full speed.

[Smac770]

If the coolant temp sensor OR the Ambient air temp sensor are unplugged/faulty, the fans go full speed.

But you'd see the ECM running the PWM duty cycle high at that point. And there would be DTCs to that effect. OP needs to get a scan tool so what actually happening can be seen, rather than speculating where the breakdown is.

[Jdraco592]

Turned out to be a bad CTS, although I'm still throwing a temp sensor code after clearing the computer. I guess we will see what happens!