Crank sensor code continues to set
Hi all, this Chrysler sets P0335 and P0520 as soon as the engine starts. I've scoped the CKP signal, 5v , and ground at the PCM and all look good. All the PCM powers and grounds are good. The crank/cam signal matches perfectly with known good. It will not learn the crank position with the scan tool, and my data shows that the crank signal is missing. Very Intermittently this vehicle will start running really rough (misfire data shows every cylinder missing) when it runs rough, It sets all the other codes listed above. I've only gotten this to happen once. This car is from a used car lot, they've replaced the crank sensor and the engine already trying to fix this concern. I'm thinking PCM, is there anything else I should check for? I'm guessing some of these other codes may return but I think I need to get the crank sensor issue sorted out first. TIA
Check for the proper calibration in the PCM. I had a 5.7 in a Jeep Grand Cherokee and someone put a used module with the wrong calibration installed. The jeep ran fine but would set the crank sensor code immediately on start up.
Dane don’t forget to wiggle test the wiring and also try gently tapping on the ECM to see if the misfire can be brought on . Regards Dave T... p.s try taking readings at the crank sensor it’s self .
Check pin fitment at the PCM. Someone may have backprobed the CKP terminals at the PCM connector and spread them. The signal could be good at the outside of the terminals, on the wires, but the PCM doesn’t see the signal because the terminals are spread and not touching the pins on the circuit board. As suggested you could try wiggling the PCM connector while cranking and see if it starts. HTH.
In looking over your code data, I see circuit codes for the TPS, oil pressure sensor & CKP. The real thing that caught my eye is the 122, 222, & 123 codes, which are voltage high & voltage low codes. Any time I see something like this, I want to go and check the VD on the grounds. By any chance these sensors sharing the same power or same ground?
These models are common for wiring harness damage around corner of valve cover passenger side braking, burning heat from exhaust not routed properly...wiggle that harness with engine running
Thank you all for your responses! Karl, the calibration is not current but it is a correct calibration number for the vehicle. David, Allan, and Luis, I forgot to mention in my initial post that I had wiggle tested the engine harness and tried tapping on PCM as well as throttle body and checked pin fitment at PCM. Albin, the throttle body, EOP, and CKP sensor share a 5v reference. The CMP…
For giggles, pull the pcm connectors off and look for coolant. I’ve had a few jeeps with that engine which is going to be the same setup . They had those codes and some more. Problem was coolant temp sensor leaking and went through the wiring all the way to the pcm.