TPS Problems

CROSER96

MEMBER
1997 CHEVROLET CAVALIER
4 CYL
FWD
AUTOMATIC
165,000 MILES

I have a 97 chevy cavalier 2.2L that has had cel all winter which reads TPS vlotage low. I have replaced the sensor a couple of times. I have also taken the car to my mechanic and he believes it has a bad computer and possible wiring issues. A few weeks ago the it began to warm up and the cel went out and the car is running fine. Would the change in weather have an affect on wiring issues or the computer. I remember the same thing happening last year at this time and then the cel came back in the fall.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

The sensor can't cause a low voltage code unless the element is cracked near one terminal and that won't be intermittent. This is typically caused by a break in the 5.0 volt feed wire to the sensor. That same circuit feeds other sensors too so if they aren't setting codes, the break has to be between the splice and the TPS. A corroded splice is very common.

Measure the voltage on the three TPS wires. One must have 5.0 volts, one will have near 0.2 volts. The middle, (signal) wire will have between 0.5 and 4.5 volts depending on throttle position, and it will have 5.0 volts if you measure it with the connector unplugged from the sensor. Some signal wires will read 0.0 volts when the connector is unplugged but 5.0 volts is much more common.