Buick Rainier AWD Problem


Original poster
Dec 19, 2011
My wifes 2005 Rainier AWD is not working. Did a good visual inspection but nothing looks broken or abnormal. A scan tool was run on it and multiple codes were present. This is a daily driver and no lights were illuminated on the dash. I have acecess to a Genisys scan tool so I can run various tests.

It does have a Code C0055. VSS Circuit

It also has many other codes

B1440 Power Mode Master input circuit
B2961 Key Ignition switch failure
B1055,B1025,B1045- All Audio codes
B3606 Foot pedal position circuit
B1830 Lumbar forward swith circuit
V1000 Class 2 data link malfunction

The car runs and drives out great. Where should I start?
Thank you for all the help!


Dec 4, 2011
What do you mean by awd isn't working? How can you tell and how is it acting? The vss code may be related, but I'm not really familiar with the full time AWD system. Maybe if the vehicle thinks different wheels are going different speeds it defaults into 2wd mode? That's only a guess though I really am not sure.


Dec 8, 2011
As always when one has with strange and seemingly unrelated electrical issues with our platform, replace the ignition switch. Even if it is not the issue, they are known to go bad and you eliminate one major possibility for little cash.

-- Dan Meyer :coffee:


Lifetime VIP Donor
Nov 19, 2011
Portland, OR
The TCCM needs to know how fast the vehicle's moving to apply the proper amount of torque to the front differential when it detects wheel slippage. I assume you punched it on slippery surface to the point where it detected wheel slippage?

How many miles, and have you been changing the transfer case fluid religiously every 50K?

What does the scan tool say it thinks the speed is? Front driveshaft versus rear driveshaft? I assume it's one that can read the data, not just codes?

There is a bunch of wiring, and two sensors on the transfer case. Actually three. One is for VSS to drive the speedometer, and the other two sense the front and rear driveshaft RPM for the TCCM.


Original poster
Dec 19, 2011
Thanks for all the replies. The way I know it was not working was I put it in the air on a hoist and put it in drive. The front drive shaft would not turn. Replaced the ignition switch and everything is working great. Only downfall was I discoverd the front axle disconnnect had a bad coupler/spline in it. Took it apart and ended up replacing the whole assembly and the intermediate shaft.

Roadie- I bought this with 90k on it. Previous owner had everything serviced correctly. First thing I did was changed all the fluids.

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