P0101 code

[bnick70]

hello, my name is Brad. I have a 2006 CHEVY 2500HD 6.0L. Originaly had codes: Knock sensors & multiple misfires. Replaced knock sensors. one was indeed bad. the knock sensor went off but multiple misfire remained. Checked for intake leaks, plugs, wires & all fuel injector connections. Cleared the code, started up the truck & engine light came right back on. scanned it & the codes that come up were P0641 & P0101. I replaced the MAP sensor & the P0101 cleared itself. But now i still have the code: P0641, still running rough & now i noticed the oil gauge sometimes works sometimes doesnt. Any help would be appreciated...

[newdude]

P0641 sets for the MAP and for the oil pressure sensor. I'd pop an oil pressure sensor in and see what happens.

[bnick70]

Okay. I will let you know Thanks...

[Formulabruce]

It means your missing the logic voltage ( 5 volts) to a couple sensors. This is supplied by the PCM... Have had to change a PCM to fix this in the past... Good luck

[Dixon700]

Have you resolved your issue?

[bnick70]

Put a new oil pressure switch in. Still doing the same thing.Still throwing P0641 open circuit 5 volt. When i removed the intake to replace the knock sensors I moved the harness out of the way towards the fire wall. someone mentioned to me that i most likely shorted a wire somewhere. This code only started coming up after I replaced the knock sensors & harness.

[bnick70]

I also tried driving the truck & the low oil pressure came up on dash and the engine seemed to go into a limp mode. then the engine shut off. I had it towed back to house. Not once did the valves rap like it wasn't getting oil. As of now the truck will start right up.

[davester]

Yes, now you get to trace the wiring for the oil pressure switch, checking for cuts/rubbing of the insulation on the wiring. Fun stuff.

[bnick70]

Update: Apparently the first oil pressure switch new in box was also bad. After hours of checking all wires for wear & shorts I decided to purchase another switch and that's what it was all along. Bought the first one online for 1/3 of what I bought the second at Advance for. I guess you get what you pay for. Now it throws multiple random misfires only when driving at 62 mph and above. Any ideas? It idles steady. Has new plugs. Wires? Ignition Coils? Injectors? Any help appreciated.

[vucelick]

I have seen knock sensors bad right out of the box. Non-OEM knock sensors, in my experience, are never a good bet.

[Dixon700]

Update: Apparently the first oil pressure switch new in box was also bad. After hours of checking all wires for wear & shorts I decided to purchase another switch and that's what it was all along. Bought the first one online for 1/3 of what I bought the second at Advance for. I guess you get what you pay for. Now it throws multiple random misfires only when driving at 62 mph and above. Any ideas? It idles steady. Has new plugs. Wires? Ignition Coils? Injectors? Any help appreciated.

Are the new plugs factory ac Delco? I guess there tends to be issues when using other brands from what I've read.