2004 TDI with BEW engine - Hard to start

[Mavrick]

I just had quite a day with this car. Came into the shop with a hard to start, sometimes no start condition. In tank fuel pump was inop, so we started by replacing it and this changed nothing. Did a lot of research on the internet and realized that a LOT of people with 04 BEW TDI's have this same problem. Extended crank (10-20seconds or more), with trouble code relating to crank sensor - implausible signal. The problem lies in the harness from the crank sensor connector up to the control module beneath the wiper cowling.

Long story short, test for key on voltage on the 3 wires of the harness going to the crank sensor. White and brown wires should have 2.5v or close to it. The BLACK wire should be grounded with key on or off. In my case, the black wire had 2.5v on it, due to being shorted to the white wire close to the control module.

The FIX is to simply cut the black wire on the engine harness side of the crank sensor connector and seal it from the harness (essentially ENDING/DELETING the factory harnesss black wire), and grounding the black wire coming from the crank sensor.

In all my research, nobody posted a FIX so hopefully this helps some people out and saves them from going to the dealership or dealing with this problem.

I believe this fix relates to TSB #TSB 2010461

 

[AARodriguez Corp.]

I just had quite a day with this car. Came into the shop with a hard to start, sometimes no start condition. In tank fuel pump was inop, so we started by replacing it and this changed nothing. Did a lot of research on the internet and realized that a LOT of people with 04 BEW TDI's have this same problem. Extended crank (10-20seconds or more), with trouble code relating to crank sensor - implausible signal. The problem lies in the harness from the crank sensor connector up to the control module beneath the wiper cowling.

Long story short, test for key on voltage on the 3 wires of the harness going to the crank sensor. White and brown wires should have 2.5v or close to it. The BLACK wire should be grounded with key on or off. In my case, the black wire had 2.5v on it, due to being shorted to the white wire close to the control module.

The FIX is to simply cut the black wire on the engine harness side of the crank sensor connector and seal it from the harness (essentially ENDING/DELETING the factory harnesss black wire), and grounding the black wire coming from the crank sensor.

In all my research, nobody posted a FIX so hopefully this helps some people out and saves them from going to the dealership or dealing with this problem.

I believe this fix relates to TSB #TSB 2010461

Great post! Going to try that out later.

 

[turbocharged798]

I already have a complete pictorial how-to on the BEW hard start TSB:

http://forums.tdiclub.com/showthread.php?t=328868

 

[Mavrick]

Good for you! Wish i could have found that before i spent all day figuring it out without the TSB!

I can appreciate your effort, but grounding one wire under the hood is a lot easier than pulling the wiper cowling off etc. No VW part or ECM reflash required.

 

[turbocharged798]

I was just following the TSB I was provided with. It did not mention grounding the sensor to the chassis.

 

[Mavrick]

No, its grounding through the ECM. I wonder if that ECM pin is already grounded all the time, or if the reflash tells it to ground that pin.

Either way, its grounded with key on or off so either way should work just fine.