GM-Tech Help

[Polak]

OBD-II indicated P0343 (Cam Position Sensor Circuit High Input).

 

Changed the CPS, cleared the codes, and now it's back

 

Did I miss something? Could the CPS I bought have been bad? Could there be another reason it's tossing this code?

 

Any help here is appreciated!

 

A.J.

[Haulin' 8.1]

It could be a problem in the wiring, ECM, etc. You'll really need a shop manual with wiring diagram to diagnose this condition correctly.

But here's the deal. The cam has a thin metal half circle sticking out on the end that spins around with the cam body traveling in and out of the cam sensor slot. If the metal is bent, damaged, missing, you'll get this code with a new sensor.

 

I don't know how easy it is to see because I've never tried it but it's fesible to remove the sensor and peer into the hole with lights and or mirror whatever and rotate the engine you should see the metal half the time and air the rest. 50-50 as it rotates in and out of view. If not you'll have to open it up and repair it to turn the light off and restore quick starting and better driveability, mileage. It runs fine without it but not as good. Remeber that the camshaft rotates at half crank speed.

 

Vernon