2004 LeSabre VSES Stability System Question for GM Tech


pcmos
06-21-2011, 12:19 AM
I'm curious to know if there is any sort of calibration function available in the tech 2 for the ABS stability system. I have a yaw rate sensor reading that appears to be skewed. After replacing the yaw rate sensor with a brand new dealer part, the reading is also skewed but in a different direction. I've read that some vehicles have a built-in zero point calibration for the accelerometer and the yaw rate sensor. Frankly it seems like the EBCM has lost the zero point calibration for the yaw rate sensor on my car. It's reading a constant state of spin. I'm getting constant stability system warnings on the dash and nobody can seem to diagnose the problem because it never sets a code. This problem has been driving me nuts for a year now and the dealer technicians are totally lost. I've replaced everything under the sun including all four wheel bearings because I was told the problem was probably with a wheel speed sensor. After pouring through the factory shop manual I can't find any mention of a VSES calibration routine. It seems crazy that there isn't one.

pcmos
09-14-2011, 09:44 PM
After almost a year of struggling with this problem I finally got around to replacing the steering wheel position sensor. The stability system warning messages have ceased and the system appears to be functioning normally. Unfortunately I still have a slightly skewed yaw rate sensor reading. The sensor error must be below the acceptable limits established by the control software because it doesn't seem to trip a code or warning. I'd still love to know if the Tech II had a calibration routine for the VSES system.

stuzman
09-16-2011, 05:14 PM
After almost a year of struggling with this problem I finally got around to replacing the steering wheel position sensor. The stability system warning messages have ceased and the system appears to be functioning normally. Unfortunately I still have a slightly skewed yaw rate sensor reading. The sensor error must be below the acceptable limits established by the control software because it doesn't seem to trip a code or warning. I'd still love to know if the Tech II had a calibration routine for the VSES system.

I'm pretty sure there is a routine in the special functions section of the Tech 2 that will calibrate the steering wheel position. Basically, once the car alignment is checked, the steering wheel is turned to the correct position. I can't remember the exact nomenclature, but there is a PID which displays the number of degrees of the steering wheel's position. Once the wheel is in the correct position, a value of 0 is entered and you're all set.

Tech II
09-17-2011, 01:23 PM
The reset is in the ABS section....

Once you are there, the Tech II instructs you how to turn the wheel....

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