service stability system

[arvee30]

does anyone have a clue as to why the service stability system indicator goes on? i looked at it in every possibly angle and i come up with nothing....

[markwb]

What is the year & trim level of your Bonneville? Sounds like a 2000+ SSEi. Anyway, it could be any number of things. You'll have to pull codes with a scan tool to get more specific detail. There are several components that make up the stability system. To name a few: steering wheel position sensor, yaw & pitch sensors (accelerometers), and the wheel speed sensors. All these sensors provide input to the stability system. Hope this is a little help. Good luck with it, give us some feedback if you resolve the problem.

[Bill Talbot]

Originally Posted by markwb

... There are several components that make up the stability system. To name a few: steering wheel position sensor, yaw & pitch sensors (accelerometers), and the wheel speed sensors....

I'm wondering why Mark knows this information when both my local dealer shop and the GM web site are so clueless to what's causing this on my 2001 SSEi. Guess I'm just thankful at this point that someone's willing to point me (us) in some direction. Up until now, all I've gotten is the run around and a rest computer (which minimized the frequency).

When my car started warning to Service Stability System and I couldn't get answers, I started recording when and where it occured. So far it looks like: Accelerating; Cruising; Decelerating; Cornering; Straight a ways; Rough roads; Smooth roads; and Parked with the engine at idle. Too bad the on-board computer can't relay it's dismay (and GM doesn't know where to start in solving this).

[ttower]

We have had the same problem on our 2000 SSEi since we bought it with 55k. Dealer changed tires,rotors,pads. still get same problem. We have not been able to cure this problem.

[GMMerlin]

The vehicle stability enhancement system (VSES) includes an additional level of vehicle control to the EBCM. The VSES is activated by the EBCM calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the ABS pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.

Your Bonneville uses the Delco/Bosch 5.3 ABS system with VSES (stability)
To diagnose the system the tech will have to follow service information in the brakes section..there are codes stored in the Chassis section of the Tech 2.