1994 Chevy k1500 350 TPS Code 22

[Dustin Jackson]

Today on my drive home my check engine light came on and at the same time the torque converter unlocked and the truck started to shift very poorly. What’s strange is that when I turned the truck off and back on the check engine light went away and the problems went away too.
I scanned a code 22 which I’ve had before and thought I resolved it by replacing the TPS a few times but it happened again today.

One video said to jump the gray and blue wires of the TPS connector and that should pop a code 21 but also it would prove the wiring between the TPS and ECU is good but it didn’t pop a code 21 so that suggests that there is a break in the TPS wiring.

Are there any common areas I should look for a break in the wiring? Also any reason this problem would happen Intermittently and be fixed by turning the truck off and back on again?

 

[Hoesgottaeat2]

I wouldn’t be surprised if the sensor is bad again. More and more a common issue. It can be tested while still in the truck, unplugged with an ohmmeter. Run it through the range of motion and the resistance should change.
With it being intermittent it can be sort of like chasing a ghost. But I suspect it will become more and more prevalent as time goes on if the sensor is failing.

 

[Hoesgottaeat2]

Wouldn’t hurt to clean the connector while you’re at it too.

 

[Dustin Jackson]

@Hoesgottaeat2 I would do that but here is the problem. According to this video a way to test the TPS wiring is to jump the blue and gray wires and this will trigger a code 21 if the wiring is healthy, when I did it no code 21 happened. Also the truck driving great just sometimes it has a code 22, it happened once in the morning but didn’t happen for the rest of the day.

 

[Hoesgottaeat2]

@Hoesgottaeat2 I would do that but here is the problem. According to this video a way to test the TPS wiring is to jump the blue and gray wires and this will trigger a code 21 if the wiring is healthy, when I did it no code 21 happened. Also the truck driving great just sometimes it has a code 22, it happened once in the morning but didn’t happen for the rest of the day.

Ok, I watched the video. I was referring to testing the sensor, not the wiring as shown in the video. The sensor is basically a variable resistor and can be range tested or “sweep” tested as I’ve heard it called. A smooth change in resistance can be seen when tested with a multimeter on the “ohm” setting and manually moving the sensor through its range of motion(while unplugged). A bad sensor may not throw a code in all positions.
From what you indicate, I still believe a corroded connector is possible here. If you discover or suspect the connector is the issue, I see them fairly inexpensive on RockAuto.

1994 CHEVROLET K1500 SUBURBAN 5.7L V8 Throttle Position Sensor (TPS) Connector | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

 

[Eman85]

No common failure point that I know of. This is part of the joy of a 30yo vehicle. I'd start with each end of the wires. Pull the PCM and unplug the connectors and look for corrosion.