2004 Passat Powertrain Databus faults

[merkerguitars]

I have a 2004 Passat in the shop, no PRNDL display, transmission stuck in 3rd gear due to nothing talking to each other. Apparently this started after I did an immobilizer defeat on the ECU (I think this is actually a case of the no communication causing the car to not start).

So far I have unplugged everything on the can bus circuit for powertrain (steering angle sensor, tcm, airbag, abs) and no dice.

I swapped a junkyard cluster in, nada, different ecu and nada.

Anyways here is an autoscan. Ignore some of the fault codes due to the steering wheel being removed.

Monday,21,November,2022,17:33:01:49158
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64
VCDS Version: 22.3.1.4 (x64)  HEX-V2 CB: 0.4615.4
Data version: 20220407 DS337.0
www.Ross-Tech.com


VIN: WVWPD63B14P196790   License Plate:


Chassis Type: 3B (3B - VW Passat B5 (1997 > 2005))
Scan: 01 02 03 08 15 16 17 19 35 36 37 46 47 55 56 57 58 75 76 77
        
 
VIN: WVWPD63B14P196790   Mileage: 304230km-189039miles
-------------------------------------------------------------------------------
Address 01: Engine        Labels: 06B-906-018-AWM.clb
   Part No SW: 4B0 906 018 DQ    HW: 8E0 909 018 A
   Component: 1.8L R4/5VT     G   0060 
   Revision: 00000000    Serial number: VWZ7Z0C8673576
   Coding: 0016751
   Shop #: WSC 20108 444 84414
   VCID: 73B0D6DEB7A928F3C2D-5160
   VINID: 9E69E05060D20448012461C900F57F0306

1 Fault Found:
18056 - Powertrain Data Bus
            P1648 - 004 - Failure
Readiness: 0110 1101

-------------------------------------------------------------------------------
Address 02: Auto Trans        Labels: 01V-927-156.lbl
   Part No: 3B0 927 156 AQ
   Component: AG5 01V 1.8l5VT USA 1213 
   Coding: 0001102
   Shop #: WSC 00028 028 00001
   VCID: 75B4E8C6B9DD36C3EC9-5160

1 Fault Found:
18262 - Powertrain Data Bus
            P1854 - 003 - Hardware Malfunction

-------------------------------------------------------------------------------
Address 15: Airbags        Labels: 6Q0-909-605-VW5.lbl
   Part No: 1C0 909 605 C
   Component: 09 AIRBAG VW61 04   0003 
   Coding: 12345
   Shop #: WSC 00028 
   VCID: 2412E58247C7FF4B8B7-4B3C

2 Faults Found:
01312 - Powertrain Data Bus
            37-00 - Faulty
00588 - Airbag Igniter; Driver Side (N95)
            32-00 - Resistance Too High

-------------------------------------------------------------------------------
Address 16: Steering wheel        Labels: 1J0-907-487-A.lbl
   Part No: 1J0 907 487 A
   Component: Lenkradelektronik   0005 
   Coding: 00118
   Shop #: WSC 00028 
   VCID: 2F381AAE1E014C13665-5160

1 Fault Found:
01426 - Controls in Steering Wheel (E221)
            49-00 - No Communications

-------------------------------------------------------------------------------
Address 17: Instruments        Labels: 3B0-920-xx5-17.lbl
   Part No: 3B0 920 929 BX
   Component: KOMBI+WEGFAHRSP VDO V07 
   Coding: 07235
   Shop #: WSC 00222 
   VCID: 7EA6F7EA89EB759BBD3-513C
   WVWPD63B14P196790     VWZ7Z0C8673576

2 Faults Found:
01177 - Engine Control Unit
            64-10 - Not Currently Testable - Intermittent
01312 - Powertrain Data Bus
            37-00 - Faulty

-------------------------------------------------------------------------------
Address 19: CAN Gateway        Labels: 6N0-909-901-19.clb
   Part No: 6N0 909 901
   Component: Gateway K<->CAN    0001 
   Coding: 00006
   Shop #: WSC 00000 
   VCID: 70BAD9D2C3BF13EB3FF-513C

1 Fault Found:
01312 - Powertrain Data Bus
            37-00 - Faulty

-------------------------------------------------------------------------------
Address 46: Central Conv.        Labels: 1C0-959-799.lbl
   Part No: 1C0 959 799 C
   Component: 08 Komfortgerát HLO 0003 
   Coding: 00258
   Shop #: WSC 00028 
   VCID: 372822CEE65184D33E5-4B1E

   Subsystem 1 - Part No: 1C1959801
   Component: 08 Tõrsteuer.FS KLO 0202 

   Subsystem 2 - Part No: 1C1959802
   Component: 08 Tõrsteuer.BF KLO 0202 

   Subsystem 3 - Part No: 1C0959811
   Component: 08 Tõrsteuer.HL KLO 0202 

   Subsystem 4 - Part No: 1C0959812
   Component: 08 Tõrsteuer.HR KLO 0202 

No fault code found.

End----------(Elapsed Time: 04:47, VBatt start/end: 13.0V/13.1V)-----------

 

[Jef]

Apparently this started after I did an immobilizer defeat on the ECU

Plug up everything but the ECM, clear codes and see what you get.

 

[merkerguitars]

Plug up everything but the ECM, clear codes and see what you get.

Same result unfortunately.

 

[jyoung8607]

So far I have unplugged everything on the can bus circuit for powertrain (steering angle sensor, tcm, airbag, abs) and no dice.

Your ABS is conspicuously missing from the scan, and if memory serves, this era of ABS modules had a failure mode where they'd take down the CAN bus when they were dying.

Sure you tried disconnecting ABS? Not just fuse pull, disconnect all wiring.

 

[merkerguitars]

Your ABS is conspicuously missing from the scan, and if memory serves, this era of ABS modules had a failure mode where they'd take down the CAN bus when they were dying.

Sure you tried disconnecting ABS? Not just fuse pull, disconnect all wiring.

Tried it with the abs module disconnected, still no dice. Also I did learn I can not scan the ABS module either.

 

[merkerguitars]

The vehicle also does have an aftermarket radio installed. I know a radio is on the comfort bus and not the powertrain bus, but would that have any affect on it?

 

[PetrolDave]

I know a radio is on the comfort bus and not the powertrain bus, but would that have any affect on it?

No, the CAN Gateway isolates the different CAN bus sections, and the CAN Gateway is only reporting a fault on the Powertrain CAN bus.

 

[Jef]

Is the TCM wet or dry?

 

[merkerguitars]

I do own a scope, anything i should scope on the powertrain data bus?

 

[merkerguitars]

Is the TCM wet or dry?

Tcm was nice and dry, even the connector looked good, no signs of corrosion at all.

 

[Badea_Cristian]

did you try with steering wheel module disconnected and abs as well?
If this doesn't work try to disconnect from cluster pins 8 and 9 and check if fault on power train persist.

 

[merkerguitars]

did you try with steering wheel module disconnected and abs as well?
If this doesn't work try to disconnect from cluster pins 8 and 9 and check if fault on power train persist.

Yup tried it with the steering wheel module and abs, I will try the pins 8 and 9.

 

[Badea_Cristian]

Yup tried it with the steering wheel module and abs, I will try the pins 8 and 9.

pin 8 and 9 are the comfort can bus connection for the rest of the modules....maybe this one it's blocking power train

 

[merkerguitars]

I figured it out!

So tonight after everyone went home I decided to start from scratch, double checked tcm, nope, different cluster nope, connectors at bulkhead for ecu, nope.

Double checked the wiring diagrams again, well there are connectors in the a pillars on the left and right that are junctions for the can bus, unplugged the airbag one on the right....nope....unplug the tcm one on the right side....nope.

Doubled checked the diagram....well there is an abs one on the left....unplug it and bam everything came back to life!.

Started to follow the abs harness down to the firewall and mice eaten wires