Service stability system and tire pressure faults
 

My Bonneville SSEi 2000 had recently a message coming up to service my stability system but when going to the dealership they want $80 for a diagnostic. There are no computer codes showing up when connecting the code reader. Then a little later I had the tire pressure sensor showing up, but there is no tire with low pressure. The tire pressure sensor is more presistant than the stability fault showing. What could be here the problem?

Hopefully there is somebody out there that can help me with this.

Thanks

Belga

Welcome, Belga. When the service stability system warning comes on, does it also disable the traction control and anti-lock brakes? if so, you could have a bad wheel speed sensor in one of the hubs, which could also cause problems with the tire pressure warning - although the stability system generally gets set first.

If the TC and ABS is not disabled, the most common cause is the steering position sensor. None of these codes will show up in a standard code reader. A Tech II scanner, or another capable of reading the ABS/TC is needed.

If you haven't already, try this for the tire pressure warning. Check to be certain that the pressure is equal (within a pound - two at most) in each tire. Then, on your DIC (digital information center) on your dash, press the select button until "Tire Pressure" is displayed, It will probably say low. Then hold the reset button until it resets, and shows normal. It could take about 5-7 seconds for this to happen.

Archon,

Thanks for responding. The TC and ABS are not disabled when the warning sound comes on, and then it disappears again later on. I went to Autozone and they verified the codes but nothing then I passed by again while the code was on and also nothing. So as you mentioned I got to verify it when a different reader. The suggestion you gave for the pressure sensor I already tried out but no luck. I'll try once more and make sure about the pressure in each tire. But this last warning is very presistant and almost continously. The TC warning used to be more but has been less lately and actually does not affect the performance of the car. Two weeks ago we were on vacation in Mexico with is not so good roads 1500miles and no problems.
So I'll try it out and I'll let you know later on this week or next.

Thanks

Belga

I recently had a slow leak in one of my tires. During the trip on which I noticed it, I pulled into a Sears to have it patched. Once the patch was installed, I drove out, and before I left the parking lot, the tire fault came back. Turns out all I had to do was use the computer on the dash, scroll to the tire pressure display and hold down the Reset button for ten seconds or so.

Have you had any recent interaction with your tires?

The tire pressure low is (as stated above) accessed vis the DIC. Once it is set, you can have all the tires at exact pressure, start the car and it will go off again. It is a persistent code when set, untill you reset it. So if you follow the steps of

If the new reading is still equal across all tires, then it's definitely not the tire or rim. Tire pressure is determined by the abs sensor reading rotations per mile. If a tire reads outside a certain variance, then the tire inflation system sets the code in the DIC. This code remains until reset, regardless of actual pressure at the tires.

If a wheel sensor is bad, the traction control and abs should be disabled and the service stability system error should show. I'd think eliminating the actual tire inflation question would be easiest to start with. (no scan tool needed for this).

I hope this helps diagnose the problem.