# Air Suspension Module failing all the time



## Robotman (Apr 26, 2013)

Hi Audi friends 

I am troubleshooting a Level control problem in an old Audi Allroad where the Suspension Level Control module fails on regular basis. It started out as a temporary fault, the local Audi dealer replaced the Control module and the vehicle worked OK for a couple of weeks. The Control module failed again and again, worked OK when the dealer had the car in the workshop, when the owner picked up the car the Control Module failed again. 
In the end the Audi Dealer wanted lots of money for all the failed Control Modules they swapped and the owner did not want to pay, he had already paid for repairing the car. In the end they settled half-way and agreed they were not interested making business together again. The Audi Dealer gave thumb up for having others to look into this but is not doing anything that can help out... This is how I cam involved. I am a certified autoeletrician by trade but work now as a teacher teaching electronics. The car owner is a friend. 
Description of Fault. 
The Suspension Level Control Module J197 fails after short time. 

The following fault codes are present: 
01575	Control Switched OFF 35-00	Permanent 
65535	Internal Module Memory Error 00-00	Permanent 
01777	Redundant signal path from controls for vehicle leveling (E281) 30-00 open or short to + 

The last error message, 01777 Redundant signal path only appears after pressing the manual UP button on the display. Before pressing the UP button the display show two LED indicating level and the green LED for UP and DOWN buttons are ON. This vehicle do not have the orange "MAN" LED but have a warning lamp in the instrument cluster for the suspension module that is alwaus ON. 
Pressing the DOWN button do not make any difference but pressing the UP button switch all lamps on the display OFF, both the lamps for the switches and the two for level control. 

Done so far. 
I have installed diodes to suppress transient current from the solenoids controlling the air valves and the relay for start and stop of the compressor. Although the driver ICs is supposed to handle coils the transients from air valves use to be huge and this was no exception, peaked the Oscilloscope at 3000 volts! The diodes removed this totally. Doing some math on the circuit the transient is just on the edge of what the driver IC can handle. I also see newer cars do have diodes. 
After installing the diodes a used Suspension Level Control Module was installed. I was not able to control the vehicle from the display but using the "Ross-tech" diagnostics tool I could test the box and it appeared to be OK. During the test it lowered each corner and leveled up afterwards, just perfect. This told me the compressor was OK and the valves did work OK. All four level sensors works OK all the time, even when the system is not working. Basically, all inputs are OK, outputs not OK. 
Tested signal from door switch coming in on Pin #6 for short and spikes. 
Tested the “K wire” going to J197 Pin #4 for short and spikes. 

I would be very happy if anyone can shine some lights on this problem. It is too expencive to replace the control modules all the time. 
Best Regards 
Dagfinn Topland 
Norway 
The following is a full fault code scan of the vehicle. Note that the fan has been disconnected as a part of the work on the vehicle; the instrument board is partly dismounted. 


VCDS Version: Release 11.11.5 
Data version: 20121222 

Thursday,02,May,2013,14:58:43:17644 

Chassis Type: 4B - Audi A6 C5 
Scan: 01 02 03 06 08 15 16 17 18 22 34 35 36 37 45 55 56 57 65 67 
75 76 77 

VIN: WAUZZZ4B83N045530 Mileage: 237240km/147414miles 
------------------------------------------------------------------------------- 
Address 01: Engine Labels: 059-907-401-AKE.clb 
Part No: 4Z7 907 401 B 
Component: 2.5l/4VTEDC G000AG D09 
Coding: 01016 
Shop #: WSC 36510 
VCID: 3C7D921A2C2F4BF83D4 
WAUZZZ4B83N045530 AUZ7Z0B2212216 

1 Fault Found: 
01375 - Valves for Engine Mounting; Stage 1 
38-10 - Output won't Switch or Short to Plus - Intermittent 
Readiness: N/A 

------------------------------------------------------------------------------- 
Address 02: Auto Trans Labels: 01V-927-156.lbl 
Part No: 4Z7 927 156 H 
Component: AG5 01V 2.5lTDI RdW 2121 
Coding: 00001 
Shop #: WSC 00000 
VCID: 4B9FC1C67981FC4084E 

No fault code found. 

------------------------------------------------------------------------------- 
Address 03: ABS Brakes Labels: 8D0-907-389.lbl 
Part No: 4Z7 907 389 A 
Component: ABS/ESP allrad D55 
Coding: 06457 
Shop #: WSC 00110 
VCID: 4A91C4C276FBE548BF8 

1 Fault Found: 
01310 - Level Control System Control Module (J197) 
49-10 - No Communications - Intermittent 

------------------------------------------------------------------------------- 
Address 08: Auto HVAC Labels: 4B0-820-043-MY2.lbl 
Part No: 4B0 820 043 AM 
Component: A6-Klimavollautomat 0105 
Coding: 00003 
Shop #: WSC 02325 
VCID: 65CB177EFF252A30B2A 

1 Fault Found: 
01273 - Fresh Air Blower (V2) 
17-00 - Control Difference 

------------------------------------------------------------------------------- 
Address 15: Airbags Labels: 4B0-959-655-AI84.lbl 
Part No: 4Z7 959 655 H 
Component: Airbag 8.4EP 2000 
Coding: 0000706 
Shop #: WSC 02325 785 00200 
VCID: 54ADDABAF4BFA3B8D54 

No fault code found. 

------------------------------------------------------------------------------- 
Address 16: Steering wheel Labels: 4B0-907-487.lbl 
Part No: 4B0 907 487 H 
Component: Lenkradelektronik D01 
Coding: 01011 
Shop #: WSC 02325 
VCID: 3163B32EFB6DB6909E2 

1 Fault Found: 
01304 - Radio 
49-10 - No Communications - Intermittent 

------------------------------------------------------------------------------- 
Address 17: Instruments Labels: 4B0-920-xxx-17.lbl 
Part No: 4B0 920 933 GX 
Component: KOMBI+WEGFAHRS. VDO D17 
Coding: 04060 
Shop #: WSC 00120 
VCID: 7F07A5167DB990E0586 
WAUZZZ4B83N045530 AUZ7Z0B2212216 

No fault code found. 

------------------------------------------------------------------------------- 
Address 18: Aux. Heat Labels: None 
Part No: 4D0 265 105 J 
Component: Standheizung Diesel D52ˆ 
Coding: 00011 
Shop #: WSC 02325 
VCID: 254B577EBFA5EA3072A 

1 Fault Found: 
01444 - Under-Voltage Shut-Off (Automatic) 
35-10 - - - Intermittent 

------------------------------------------------------------------------------- 
Address 34: Level Control Labels: 4Z7-907-553.lbl 
Part No: 4Z7 907 553 A 
Component: - 2C1A1 X019 
Coding: 25500 
Shop #: WSC 09999 
VCID: 438FE9E651D134007CE 

4 Faults Found: 
01575 - Control Switched Off 
35-00 - - 
65535 - Internal Control Module Memory Error 
00-00 - - 
01777 - Redundant Signal Path from Controls for Vehicle Leveling (E281) 
30-00 - Open or Short to Plus 
01776 - Control Head for Vehicle Leveling System (E281) 
57-10 - Electric Circuit Failure - Intermittent 

------------------------------------------------------------------------------- 
Address 35: Centr. Locks Labels: 4B0-962-258.lbl 
Part No: 4B0 962 258 N 
Component: Zentralverrieg.,DWA D37 
Coding: 06987 
Shop #: WSC 00120 
VCID: 346DBA3A047F83B8F54 

2 Faults Found: 
01370 - Alarm triggered by Interior Monitoring 
35-00 - - 
00955 - Key 1 
09-00 - Adaptation Limit Surpassed 

------------------------------------------------------------------------------- 
Address 37: Navigation Labels: 4B0-035-192-RNSD-37.lbl 
Part No: 4B0 035 192 K 
Component: RNS 4.2 H06 BNO 0105 
VCID: 254B577EBFA5EA3072A 

No fault code found. 

------------------------------------------------------------------------------- 
Address 45: Inter. Monitor Labels: 4B0-951-178.lbl 
Part No: 4B0 951 178 A 
Component: Innenraumueberw. D04 
Coding: 00102 
Shop #: WSC 02325 
VCID: 26495072C2A3E1287B0 

No fault code found. 

------------------------------------------------------------------------------- 
Address 55: Xenon Range Labels: 4Z7-907-357.lbl 
Part No: 4Z7 907 357 
Component: dynamische LWR D08 
Coding: 00030 
Shop #: WSC 02325 
VCID: 040D2AFA145FF338054 

No fault code found.


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