2004 Audi A4 CCM no communications - multiple repairs



Verified VCDS User
May 29, 2020
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Massachusetts, USA
Hello everyone. I've been working on my MIL's A4 Cabriolet over the last 6 months, it's in rough shape. Original complaints were a no crank start, no power windows, no power top. CCM J393 was found badly corroded and sitting in water. The power pin (Connector 1/11) had burned off the module and into the plug. They bought a used numbers matching CCM (#8H0 959 433 C) that I installed along with splicing in the first connector due to the damage. Wires were soldered and heat shrinked.

Module was installed, power window was rolled up enough to keep rain out, power top didn't work, still no crank. Project was benched for a while until I could bring it to the shop I work at. Module was removed from the vehicle and left inside house. Got the car to the shop finally, diagnosed starter, replaced, engine starts now. Plugged CCM into vehicle now, no power windows or power top again.

Okay, this one is a fighter. Break out the meter and scope, no continuity to drivers door module on comfort canH, opened up the door jamb sleeve and found a broken canH wire, along with several bad splices, someone had already been there. Found a used numbers matching wiring harness for the entire door so no more splices, installed it. Also found relays in the electronics box sitting in water, cleaned it up and replaced relays J271 ECM power supply and J434 starter relay as they had some corrosion.

What is now working: Headlights, Turn signals, wipers, steering wheel controls work with the aftermarket radio. On the door, power locks work, powered mirrors work, and the mirror fold in power works also.

Not working: Power windows from master or passenger switch, trunk switch on driver door, interior lights, power top (Soft top cannot be used on display).

I backprobed the comfort can lines at the ccm module, and I'll try to link or insert the waveform. One interesting thing to note is when I was scoping the comfort lines and disconnected the door module to see if it was affecting signal, the driver's door power window dropped slightly, as if you were opening the door and the window was fully extended against the top. It never went up, only down 1/2". IDK what that means other than the motor seems to be working.

I pulled the driver's seat out and pulled up the carpet to inspect all the wiring along the floor tray and up into the instrument cluster. I haven't found any breaks in the comfort CAN lines (yet?). I don't like the look of the waveform, it has this odd curve instead of being more square like I'm used to. I'm not an expert on CANbus though. I've done a lot of reading and it does seem like the comfort line in this car is a low-speed line, with the terminating resistors at each node. The waveform didn't seem to be affected by whether the CCM was plugged in or not.

Honestly, I'm almost leaning towards the 2nd CCM as being suspect. I'm not sure if it came damaged, or had been damaged by connecting it before the other wiring repairs were made? It has power and ground on connector 1, fuses seem alright as well. I can access 17-instruments and 26-roof in VCDS. I get a no communication when I try to access 09-central electronics, 15-steering wheel, and of course 46-comfort. I read the self study guide on the car and it seems like you won't be able to access J519 or J527 if the CCM is down. The only fault code in instruments is a No communications to CCM, and a no comm to radio which I believe is from the aftermarket head. Auto scan results below (the drivers seat is removed when this was scanned.)

Thank you in advance, any help is really appreciated.

Chassis Type: 8H (8E - Audi A4/S4/RS4 B6/B7 (2001 > 2008))
Scan: 01 02 03 08 09 0F 11 15 16 17 18 25 36 37 45 46 55 56 57 65
          67 69 75 76 77
VIN: WAUAT48H94K002513   Mileage: 229030km-142312miles
Address 01: Engine        Labels: 06C-909-559-ASN.lbl
   Part No SW: 8E0 909 559 L    HW: 8E0 909 059 
   Component: 3.0L V6/5V      G   0010  
   Coding: 0016754
   Shop #: WSC 00672 785 00200
   VCID: 3E25396EFC682CEB617-513C

2 Faults Found:
18107 - Powertrain Data Bus 
            P1699 - 008 - Missing Message from Steering Wheel Electronics - Intermittent
16955 - Brake Switch (F) 
            P0571 - 008 - Implausible Signal
Readiness: 0110 1101

Address 02: Auto Trans        Labels: 01V-927-156.lbl
   Part No: 8E0 927 156 Q
   Component: AG5 01V 3.0l5V  USA 0912  
   Coding: 0001002
   Shop #: WSC 00672 785 00200
   VCID: 3C213366EA743EFB4F3-513C

1 Fault Found:
17087 - Brake Switch (F) 
            P0703 - 003 - Electrical Malfunction
             Freeze Frame:
                    RPM: 0 /min
                    RPM: 0 /min
                    RPM: 0 /min
                    (no units): 0.0
                    Torque: 220.0 Nm
                    Temperature: 23.0°C
                    T.B. Angle: 0.0°
                    (no units): 4.0

Address 03: ABS Brakes        Labels: 8E0-614-517.lbl
   Part No: 8E0 614 517 H
   Component: ABS/ESP allrad      2328  
   Coding: 04497
   Shop #: WSC 00001  
   VCID: 2D070E22240EA773C8D-51CE

1 Fault Found:
01826 - Sensor for Steering Angle (G85); Supply Voltage Terminal 30 
            35-10 - - - Intermittent

Address 08: Auto HVAC        Labels: 8E0-820-043.lbl
   Part No: 8E0 820 043 AD
   Component:   A4 Klimaautomat   1219  
   Coding: 00100
   Shop #: WSC 00672  
   VCID: 6393A81A324A21032E9-513C

4 Faults Found:
01172 - Temperature Sensor; Driver's Heated Seat (G59) 
            30-00 - Open or Short to Plus
00532 - Supply Voltage B+ 
            52-10 - Supply Voltage Too High - Intermittent
01330 - Central Control Module for Central Convenience (J393) 
            49-00 - No Communications
00457 - Central Electronics Control Module / BCM (J519) 
            49-10 - No Communications - Intermittent

Address 15: Airbags        Labels: 8H0-959-655-84.lbl
   Part No: 8H0 959 655 B
   Component: Airbag 8.4EC        2015  
   Coding: 0010105
   Shop #: WSC 00672 785 00200
   VCID: 392F2A72E5460BD3545-5160

2 Faults Found:
00591 - Seat Belt Switch; Driver (E24) 
            010 - Open or Short to Plus - MIL ON
01217 - Side Airbag Igniter; Driver Side (N199) 
            001 - Upper Limit Exceeded - MIL ON

Address 17: Instruments        Labels: 8E0-920-9xx-8E2.lbl
   Part No: 8H0 920 950 E
   Component: KOMBI+WEGFAHRS. RB4 D16  
   Coding: 03201
   Shop #: WSC 00001  
   VCID: 2E05092E2908DC6BF17-5160
   WAUAT48H94K002513     AUZ6Z0C0122278

2 Faults Found:
01330 - Central Control Module for Central Convenience (J393) 
            49-00 - No Communications
01304 - Radio 
            49-00 - No Communications

Address 55: Headlight Range        Labels: 4Z7-907-357.lbl
   Part No: 4Z7 907 357 
   Component: dynamische LWR       D09  
   Coding: 00070
   Shop #: WSC 00672  
   VCID: 04518B86D734863B773-4B3C

No fault code found.

End----(Elapsed Time: 05:54, VBatt start/end: 12.1V/12.0V. VIgn 11.9V)-----


Jan 29, 2014
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Montgomery, NY, USA
VCDS Serial number
Do you have switched power for all terminal dins?
Is gateway configured proper in cluster?

Is ignition switch function correct?


Benevolent Dictator
Staff member
Jan 29, 2014
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VCDS Serial number
Not just CCM (46) but also CECM (09) is missing from that scan.

I too would suspect power problems.