1995 GMC Yukon TPS low voltage code keeps coming up

BYGDADDY8

MEMBER
1995 GMC YUKON
V8
4WD
AUTOMATIC
269,000 MILES

I keep getting a code 22 saying the tps has a low voltage. I replaced the tps, among other things such as the IAC, EGR VALVE, MAP SENSOR. When I tested the electrical connection it read 5 volts, as suggested by the book. This problem causes my transmission to shift incorrectly and kick into gear real hard. What else could be the problem?

3 Replies

JDL

MECHANIC
16,098 POSTS

You erased the code and it keeps coming back? Gray wire is ref voltage, black is ground, dark blue wire is signal. With engine idling, what is the signal wire showing. You can back-probe the connector or use a straight pin in the wire, take a reading off the straight pin, use digital multimeter. Any hole you make in a wire during testing, cover the hole when your through, super glue, nail polish or something.

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Friday, September 25th, 2009 AT 11:09 AM

BYGDADDY8

MEMBER
2 POSTS

I tested it and it read 5 volts, just like the gray wire. When the car is off and the key is in the on position, the blue wire reads.040 volts via the connector, yet the gray wire reads 5 volts still

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Friday, September 25th, 2009 AT 1:14 PM

JDL

MECHANIC
16,098 POSTS

The gray wire is ref voltage, it should read close to 5 volts, key on. With everything hooked-up, take a reading from the signal wire, dark blue, key on engine off, while you watch the voltage reading, have helper work the throttle, see if voltage reading moves up and down smoothly. If it does, I don't see a problem with the tps?

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Friday, September 25th, 2009 AT 3:42 PM