Short To Ground

[souper]

So I recently pulled my engine to do a clutch job and just finished putting everything back together. When I try to start, it turns over but won't fire up. I pulled the codes and I'm getting multiple 'Short to ground' codes. In addition i'm getting a code for coolant temp too high:

16502 Engine Coolant Temp. Sensor (G62): Signal too High : P0118 - static - No indication on display      

17633 Fuel Injector for Cylinder 1 (N30): Short to Ground : P1225 - static - No indication on display      

17635 Fuel Injector for Cylinder 3 (N32): Short to Ground : P1227 - static - No indication on display      

17636 Fuel Injector for Cylinder 4 (N33): Short to Ground : P1228 - static - No indication on display      

17634 Fuel Injector for Cylinder 2 (N31): Short to Ground : P1226 - static - No indication on display      

17833 EVAP Purge Valve (N80): Short to Ground : P1425 - static - No indication on display      

17955 Boost Pressure Regulation Valve (N75): Short to Ground : P1547 - static - No indication on display      

17525 Oxygen (Lambda) Sensor Heating Circuit: B1 S2: Short to Ground : P1117 - static - No indication on display      

17843 Secondary Air Pump Relay (J299): Short to Ground : P1435 - static - No indication on display      

17938 Camshshaft Timing Adjustment: Short to Ground : P1530 - static - No indication on display      

17829 Secondary Air Injection Solenoid Valve (N112): Short to Ground : P1421 - static - No indication on display      

17697 Boost Pressure Control Valve (N249): Short to Ground : P1289 - static - No indication on display      

17909 Fuel Pump Relay (J17): Short to Ground : P1501 - static - No indication on display

After searching I thought for sure I fried the fuel pump relay somehow so I replaced that with no luck. Now I'm thinking I actually knocked a ground wire lose somewhere in the bay. Anyone know where this problem could be? I also checked fuses 28 and 29 but they appear to be fine.

[souper]

Bump. While checking all of the harness plugs I discovered that the coolant temp sensor plug wasn't sitting on the sensor fully. The clip inside the plug was sticking out, preventing the plug from clipping into place. Fixing it didn't solve the problem however.

I also noticed one of the fuel injectors wasn't seated properly in the manifold. After moving the rail, the injector popped out and gas spilled out. Fixing this also did not improve things. This proves the pump is working though which is a good sign.

I did an 'Active Test' with my VAG tool and i'm getting power at all the plugs... N75, N80, N249, fuel injectors, etc. So the codes i'm getting are bogus.. at least most of them.

If anyone has advice i'd appreciate it. Really don't want to have this thing towed to the dealer.

[xdewaynex]

Did you mess with any of the grounds around the firewall area?

[Seerlah]

All grounds for the engine harness are on a stud by the ECU weather box, on the engine bay side of the false firewall. Inspect those grounds. Within the harness, grounds iirc splice into other ones along the way to the stud. Some iirc go back into the weather box and go to wherever from there. Short to ground is most likely a positive wire exposed and touching metal on the chassis. Standard short to ground explanation, or the previous mentioned of the actual ground wire not having a good connection.

But another thing you want to look into is your crank position sensor. Take it back out the block and inspect any shavings on it. If they exist, clean them off and place back into the block. This sensor is funny and can make your vehicle do weird thing, like you are explaining...with no DTC relating to the crank position sensor. These are cheap at like $25 shipped brand new Bosch. But to get them at that price you need to cross reference the OEM part number with Bosch and do your internet shopping for the cheapest price. I am a fairly confident this is your issue.

Check these 3 things needed for combustion:
1) Compression (compression test)
2) Fuel (take rail with injectors connected off manifold and see if they spray when cranking)
3) Spark (pull an ignition coil, put random plug in it, make sure the plug is grounded to the valve cover, and see if it sparks when cranking)

One or more of those is causing your engine to not start, and will lead you in the right direction. But I am still fairly confident it is your crank position sensor.

[souper]

The only grounds I removed were the passenger side engine mount and the one for the coil packs, both of which are firmly in place. I checked the grounds below the coolant expansion tank and they are attached and solid. No signs of wear. I will check the crank sensor next. Thanks guys.

[souper]

All grounds for the engine harness are on a stud by the ECU weather box, on the engine bay side of the false firewall. Inspect those grounds. Within the harness, grounds iirc splice into other ones along the way to the stud. Some iirc go back into the weather box and go to wherever from there. Short to ground is most likely a positive wire exposed and touching metal on the chassis. Standard short to ground explanation, or the previous mentioned of the actual ground wire not having a good connection.

But another thing you want to look into is your crank position sensor. Take it back out the block and inspect any shavings on it. If they exist, clean them off and place back into the block. This sensor is funny and can make your vehicle do weird thing, like you are explaining...with no DTC relating to the crank position sensor. These are cheap at like $25 shipped brand new Bosch. But to get them at that price you need to cross reference the OEM part number with Bosch and do your internet shopping for the cheapest price. I am a fairly confident this is your issue.

Check these 3 things needed for combustion:
1) Compression (compression test)
2) Fuel (take rail with injectors connected off manifold and see if they spray when cranking)
3) Spark (pull an ignition coil, put random plug in it, make sure the plug is grounded to the valve cover, and see if it sparks when cranking)

One or more of those is causing your engine to not start, and will lead you in the right direction. But I am still fairly confident it is your crank position sensor.

I pulled the sensor and gave it a quick wipe. It didn't have any shavings and was decently clean.. some debris around the gasket/ring but that was it. Put it back in and no difference. Do you still think it's the sensor?

[souper]

I'm going to tackle this again hopefully this weekend. If combustion checks out then i'm going to unplug the entire harness and redo the install.

On the alternator cable to the stater, does anyone know where this goes?

[souper]

So I replaced the CTS which got rid of that code. There is a nick (exposed copper) in the brown wire to the connector. I can't tell if it's partially severed, but I was able to get the car to start while pumping the gas pedal repeatedly and fast. Once fired, it idled pretty rough as the rpms peaked at 1800 rpms initially before dropping real low as it tried to maintain 800. I had to give it some gas to keep it running, but it definitely wanted to stall. I was able to fire it back up right after without pumping the gas.

I still get all the other ground to fault codes. I have a new CTS plug on the way.

After checking a few things with the VAG tool I tried restarting again but the car won't turn over... almost as if the the starter is dead. I'm fairly confident it will turn over if I leave it for awhile. What would cause this to happen? Battery appears to be fully charged.

[Cybersombosis]

I'm going to tackle this again hopefully this weekend. If combustion checks out then i'm going to unplug the entire harness and redo the install.

On the alternator cable to the stater, does anyone know where this goes?

That attaches to the bell housing to engine bolt you removed to take the tranny off at around the 9 o'clock position right above the starter.

Also after reinstalling my engine, it took a few attempts at firing her up to get the fuel lines primed. How long did you try for? It took 4-5 times for me cranking for 10-15 seconds each time before it fired up.

Doug

[souper]

That attaches to the bell housing to engine bolt you removed to take the tranny off at around the 9 o'clock position right above the starter.

Also after reinstalling my engine, it took a few attempts at firing her up to get the fuel lines primed. How long did you try for? It took 4-5 times for me cranking for 10-15 seconds each time before it fired up.

Doug

Thanks Doug. I actually attached that to the upper starter bolt. Probably fine as is but I'll relocate it to the proper one.

I've had many attempts trying to start the car but never waited 10-15 seconds.. at most probably 5. Last night I got it started by holding it longer and pumping the gas. I assume the new CTS was the main reason as there was a noticeable difference in the car trying to start with it installed.

Do you have any idea where this retainer goes? It's the only left over part after putting the engine back.

[Seerlah]

On the starter.

[souper]

On the starter.

Looks like it goes on the 12v stud? What purpose does it serve? I wonder if it could be causing the electrical issue.

[chris164935]

Check the motor mount bracket on the starter side and make sure that the ground wire is securely bolted to it and to the chassis. Also, make sure that the battery cable is firmly bolted to the starter. And lastly, make sure the 1-pin plug on the alternator harness is plugged in to the connector on the engine harness.

[souper]

Check the motor mount bracket on the starter side and make sure that the ground wire is securely bolted to it and to the chassis. Also, make sure that the battery cable is firmly bolted to the starter. And lastly, make sure the 1-pin plug on the alternator harness is plugged in to the connector on the engine harness.

I checked the 1-pin plug and the chassis ground is on there good. I reconnected the 12v from the battery and the alternator to the starter and made sure they are on tight. I managed to snap that retainer in two.. oops. The car needed a jump but once I got it running it actually felt good, and my throttle response felt normal. But after restarting everything went back to running like shit.

When I say throttle response felt normal, whenever I've managed to get the car running prior the engine took a second or two to respond after I blipped the throttle.

I charged the battery over night and this morning the car had no trouble firing up, but it won't stay running. Before I was able to keep it running while giving it gas. Now it just dies after a couple seconds no matter what. I know i'm getting combustion and fuel doesn't seem to be the problem. So far I've replaced the FPR, coolant temp and crank sensors. I'm going to replace the CTS plug tonight; maybe that kink in the wire is causing the ground issue which is preventing those parts from working when the car is running. I doubt it. Not sure what the difference is when the car is running vs just being in the on position. Alternator?

We got snow over night so i'm at the point of covering it with a tarp and calling it a quit for the winter. I really want to pull the engine again and double check everything with it out of the car but I think I lost that window.

[souper]

This might be a stupid question but where is the other end of the ground wire that attaches to the chassis @ the engine mount? Does is go to the block?

EDIT: Nevermind, just realized that was the connection to the block.

[chris164935]

Is the starter bracket bolted to the block on the front side? What year is your car? If you have DBW, you might need to do a throttle body adaptation. Beyond that, your next step might be to check the engine harness for cracks/exposed wiring.

[souper]

Is the starter bracket bolted to the block on the front side? What year is your car? If you have DBW, you might need to do a throttle body adaptation. Beyond that, your next step might be to check the engine harness for cracks/exposed wiring.

Funny you should ask. When I first removed the starter to pull the engine, there was no bolt securing the front bracket. I installed it the same way when putting the engine back in but this last go around I ended up using an old pressure plate bolt to secure it to the block.

I have an 01. I did try the throttle body adaption which didn't make a difference. I didn't get a chance to replace the CTS plug last night but that's next on my list. I'm dreading having to rip apart the harness for a thorough check of all the wires. Something i'd rather do with the engine out.

[souper]

Back from the dead. Threw in a different engine harness with no luck. I can get the car running but it fights to stay at idle. I used some jumper cables to ground block to frame and battery but still get all of the ground to short codes. Codes are triggered when car tries to start regardless of whether it actually fires up or not. The coil pack ground and the ground near the ECU are nice and tight.


According to google this appears to be a first for a 20 year old model car. I've been unable to find anyone who has had a similar issue. Bunch of short to ground codes but all intermittent which usually ends up being the relay or a fuse.

Not sure how but I could have messed up timing.. if that sounds like a cause. I didn't touch the front of the engine other than removing alternator and accessory belts, etc. Maybe bad camshaft sensor?

About to send to a shop... if anyone has any other ideas i'd appreciate the input. Thanks

[souper]

For those interested, problem ended up being bad ECU. Swapping in a different unit solved all of the short to ground codes. I'm battling a new problem now, but unrelated to this issue (I think).