[Davidg]

Hi guys,

I'm new here but a ling time lurker.
Finally scored a V10 AYH 2004 model, has 335k kms and has been reasonably well looked after.

I got the car for an absolute steal due to the PO being unable to clear the limp mode.
Have connected Vag-com and everything clears off (after 2 new G14 Varta's being installed) however I can not get ECM 2 to communicate, codes I'm getting are P1907 and P3337 or 18315 and 19793.
I've checked all fuses, disconnected both ECM's and checked connectors, left ECM 2 disconnected and ran the scan which had comms loss on all channels, reconnected, cleared all and rescanned with the same 2 codes as above.

I'm leaning towards a broken wire between both ecm's.
Having said all that the car drive terrible but no other lights on the dash.

Has anyone experienced this?
Have checked Ross tech and both 5 digit codes don't exist in their database.

Cheers
Dave

 

[chewblekka]

The ECMs are connected together over CAN-bus, then joined and run to the blue 10-pin plug in the plenum e-box. ECM pin 66 is CAN-low (orange/brown), and pin 89 is CAN-high (orange/purple). I would start by checking each for continuity from one ECM connector to the other. If you peel back the harness sheathing between the two connectors, you'll see the CAN splices.

Also check for key-on power at pins 3, 5, and 6 (red/yellow at one ECM, red/white at the other)

The CAN-bus wires are also spliced to run to each of the turbocharger actuators.

DTC 18315 is ECM to ECM communication fault, 19793 is ECM to ECM databus implausible message.

 

[Davidg]

The ECMs are connected together over CAN-bus, then joined and run to the blue 10-pin plug in the plenum e-box. ECM pin 66 is CAN-low (orange/brown), and pin 89 is CAN-high (orange/purple). I would start by checking each for continuity from one ECM connector to the other. If you peel back the harness sheathing between the two connectors, you'll see the CAN splices.

The CAN-bus wires are also spliced to run to each of the turbocharger actuators.

DTC 18315 is ECM to ECM communication fault, 19793 is ECM to ECM databus implausible message.

Absolute legend!!
Thank you sir, I'll give it look

 

[chewblekka]

Check for your grounds, constant and switch B+ too.

 

[Davidg]

Ok so I've check continuity between all the can pins, power, earth and switch B+ - everything is good, unwrapped the loom between ECM's and checked condition.
With ECM 2 disconnected, engine still runs, with the 2 previous codes remaining and an additional cam sensor code.
It would appear the ECM 2 has failed?

 

[italmind]

Currently having this exact issue on my 04 v10. Any updates?

 

[Davidg]

Currently having this exact issue on my 04 v10. Any updates?

Turned out the slave had an internal failure where it lost the CAN comms. I bought a used slave from Lithuania for $120 shipped and had it reprogramed to match the master.
Wasn't cheap to have done but I got it in and it now runs perfectly

 

[Boon]

Hey Guys. I too have a problem with my ECMs as in they are not showing up as engine 1 and engine11 on my VCDS scan!. Does anyone know is there any way you can bench test the ECM to go directly to the vcds? I remember seeing it on youtube once but I can't seem to find it anymore.

 

[Boon]

Check for your grounds, constant and switch B+ too.

View attachment 248489

Hi Chewblekka thanks for putting this bit of info up super helpful to get an idea. I have checked the earth and it seems to be fine. That is to say that I have continuity between Pin 1 and the earth lug for the convenience jumper lug on the left-hand side of the engine compartment.

Mine is a RHD.

Where should I test the continuity for the power wire or should I try to supply power externally to the PIN 18 or 3,5,or 6 to see if it activates the ECM. Note, there are no coms to ECM 11, ABS, TCM, instrument cluster or Airbags.... it hasn't been a great day...