fautly check engine lights

[outperformit 36]

Im still after several weeks trying to decide if Im going to purchase this certain 95 325i. The kid says
that it needs a new wheel sensor but does not know for which wheel. He said that the Check
engine light stays on and the technisions dont know what the problem is. Has anyone had a
faulty check engine light where it wont shut off even after passing a diagnostic test?[???1]

 

[jrt67ss350]

Yeah, my parents had a 1994 Pontiac Bonneville SSE that had a faulty EGR valve that threw a code and a check engine light. Shortly after replacing the valve, the light came on again. After clearing the codes in the computer (both by disconnecting the battery and via a code scanner), the light remained on. Had us stumped for a few days. Turned out that the computer was bad. Replaced the ECU, and it fixed it.

 

[wood_e]

A check engine light is almost never faulty...

 

[ryanf]

If there's a faulty sensor, the light usually can't be cleared until the sensor's replaced. I'm not sure why you would think it could be cleared, so perhaps I'm misunderstanding the situation.

 

[e36325is]

My check engine light was on, had to replace oxygen sensor, after that my RPMs stopped bobbling and check engine light was off

 

[jrt67ss350]

A check engine light is almost never faulty...

Very very true. I just offered my experience to demonstrate that if the faulty components have been replaced, it is possible, albeit unlikely, that the computer could be bad.