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Good evening! I have an issue with a '12 GMC Savana 3500 6.0. It's a crank no-start. Had a ckp sensor code, replaced it and it still didn't start. Checked the wires, had 4.9 volts on both the reference voltage wire and the signal wire (gray/black wire, and violet/white wire) (BTW, the 4.9 volts were constant whether or not the ckp sensor was connected). Traced them back to the PCM connectors and they look good. Connected the PCM connectors and signal wire didn't have voltage anymore, which made me happy and I thought problem had been resolved. But cranked it and scanner still didn't read RPM. Checked signal wire and it once again had 4.9 volts, along with reference wire. Is it the PCM? Is there a short somewhere I don't see? Is it time to light a Savana bonfire? Thank you for your time!
The testing steps for P0335 indicate the presence of 5V with the key on and the crank sensor unplugged is normal behavior. Further more the next steps it describes is:
Ignition ON, momentarily touch the other end of the fused jumper wire to ground repeatedly while monitoring the scan tool Crankshaft Position Sensor Active Counter parameter. The Crankshaft Position Active Counter should increment.
It's the sensors job to pull that signal wire to ground to produce a crank signal and that last test step wants you to be the sensor and see if the computer can detect the on off you'll be making..
Last edit: 10 months 2 days ago by ferris48.
The following user(s) said Thank You: Noah, Letsdothis
Greatly appreciate the reply! I'll test it out tomorrow and see what the response is. Sucks that we get bad parts so often nowadays that you can't simply rely on it being new. Oh well.
So it ended up being that the new ckp sensor was bad. ? Oh well, not the first time and I'm sure not the last! But thank you very much for that information because I really thought the PCM had gone bad. Have so much to learn about the electrical system (I'm just a newbie ?). Appreciate the help, have a good one! ?
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