: TPMS problem

07-27-10, 08:08 PM
For the last year,whenever I was driving over really serious potholes the "Service Tire Monitor" message would come on. Scrolling through the Info it was always the Left Front. So finally getting off my butt, I has a new TPM installed there under warranty two weeks ago.

Two days ago, while driving on a smooth expressway, the same message for the same sensor appeared. It stayed on until I got to my destination, and was then gone upon restarting the car.

Any ideas for me to present to my baffled service advisor?:confused:

07-28-10, 04:26 PM
It might *not* be the driver's side front TPMS? It might be one of the other three TPMS sending units? Each TPMS has to be "trained" to the receiver so that it knows which TPMS is in which wheel LF/RF/LR/RR, and if you rotate the wheels without retraining the system, it will happily lie to you about which tire is the problem i.e., the "Left Front" may actually be on any of the four corners! But surely the stealership would know this and actually tested the TPMS unit(s)?

Cadillac Cust Svc
07-29-10, 01:58 PM
I would suggest going through the Tire Pressure Monitoring System matching process (which matches the sensors in the wheels to their position on the vehicle) which is in your owners manual. The process begins on page 436 and ends on page 437. All steps required to match the sensors are on those two pages. If this process does not fix the issue then I would be glad to help you if you would direct message me about this issue. I hope that helps you. Thank you for your time.

Jeff Morris, Cadillac Customer Service

07-30-10, 10:41 AM
Thank you. I tried the matching process, but every time I did the "parking brake-lock-unlock-accessory on-hold both buttons", I got a double horn chirp. I found out to my chagrin that this indicates the END of the process, not the beginning, when I ended up with a flat LF tire waiting for that "matched" chirp.

Tried three times, same result every time. So next week off it goes to the dealer, they can use the "TPMS Diagnostic Tool" referred to in the manual...