2006 Volvo VNM64T Electrical Faults and Crankcase Pressure too high

The sensor may be bad, but I doubt that is the root cause of your problems. It sounds like your body harness may be damaged somewhere, especially since your problems seemed to begin when it got wet, then returned after it rained again. I have a 2000 VNM64T that had a bad body harness, it caused all sorts of electrical gremlins until it was replaced. Go thru the truck and disconnect the major harness connectors one by one and check for corrosion, inspect the harnesses anywhere they run or are clamped in place, pull back the wire loom to look inside, I found small punctures in my harness where a hack of a "mechanic" had used a test probe to pierce the insulation which in turn allowed road spray to enter the wire and build up corrosion over time. You may find just a loose connector somewhere that is causing voltage fluctuations, remember many sensors only send very small currents, usually less than 5 VDC at a few milliamps, the slightest corrosion to introduce resistance in the wiring harness will throw all sorts of codes and cause your BCM, and ECM to act up.

Good luck, these type of problems are the hardest to troubleshoot without proper test equipment and electrical knowledge. It takes a lot of time and patience to thoroughly trace the entire harness and inspect every connector and possible point of ingress for corrosion.

 

Is it a cummins, if so change your crankcase filter. I had the same, changed filter it went away

 

I have a 2006 with a d12. Had it 8 months and I am on my 3rd oil pressure sensor( about to be my 4th).

They just keep crapping out on me and we can't figure out why.

 

better knock on wood.

yeah, d12 absolutely rock. except for dealer only parts, and expensive parts. good luck

 

usually sensor goes bad and drivers just separate connector to disable engine protection with crankcase pressure, but onese we had bad ventilation, driver concidered sensor to be bad as usually and disconnected it.

High pressure blown valve cover. Sometimes plastic oil pan cracks. So before u disable this sensor check vent lines!

 

Hi, about the crankcase pressure sensor Yes we saw this problem often (sensor problem), about your electrical problem when it rain i'm suspecting you have a water intrusion in the electrical passthrough connector at the fire wall (LH) base on my own experience you need to be in a garage when you will open it because you may need to replace many terminals as well due of corrosion.
Ben

 

usually sensor fails. It reads higher pressure.

Volvo pressure sensors are weak. For example D12D and D12C oil pressure sensors fail and read 30 PSI with engine not running! when engine idles - read over 50 psi!

So I think, sensor is bad!