2007 Red Lightning and CEL???

[slooburn]

Hello everyone new here and looking for help. Truck has no throttle,will idle. Cranks after several seconds of turning over. Cel code 335 Crank Pos Sensor. Replaced being a 13 dollar part no change. Read that during cranking PCM reads Cam Pos Sensor. Replaced no change. Power at connector to CPS is within spec on one side and below on the other, Checked wire back to PCM and is fine. When looking at plug left side has 4.92 volts, middle good ground, right side 2.73 volt all the way back to PCM. Wondering if PCM has crapped out. Truck has 86xxx miles. Have also reset PCM three differnt ways no change. Thanks for any help.

 

[Harley Harrold]

 

[Redtruck-VA]

Any physical damage on the sensor when you removed it?

 

[slooburn]

No both sensors looked good no apparent damage just a little carbon on Cam sensor. Also have tested battery and is good. Truck stuck in limp mode and no other codes.

 

[Redtruck-VA]

I only mentioned it because on the early trucks there was a very rare occurrence of the tone wheel letting go and it would mark the sensor. Is your battery original? Check the chassis ground. Before tackling the PCM I'd replace the battery even through it checked good. My dealer sucks and won't go to them, but you might check for updates and have it reflashed if you trust them. After a reboot do you get an immediately limp mode?

 

[slooburn]

Understand about tone ring. Battery not origimal. After reboot, try to start and it turns over for several seconds before engine starts. Lightning bolt off untill cranking lasts to long and right into limp mode.

 

[Redtruck-VA]

That points at two things. first check the ASD relay it should initially be energized for 3-4 seconds without sensing crank signal. This powers the injectors, spark coils and fuel pump. A quick check is to listen for the fuel pump to run and shut down. Second would be a faulty fuel pump not getting pressure up. Pressure should be static at 58#. The crank sensor signaling the PCM that it has a cranking/running sense is critical.

 

[hemihustlin]

Pretty sure there is no asd relay after 04, damn TIPM

 

[Redtruck-VA]

Pretty sure there is no asd relay after 04, damn TIPM

Really? then forget what I posted. Actually I thought it was 08 when everything really got changed around. I don't know anything about the new trucks. Sorry...

 

[RonJon '06]

I read somewhere that the crank position sensor has a 5V power supply, a ground, and the third will have a square wave, either 5V or 0V so that 2.73 reading looks out of place. Also I guess you can test the sensor while it's out by touching the end to something metal while turning the key.

 

[slooburn]

Well after days of chasing this problem finally fixed... Unhooked battery overnight next morning cranked and drove fine. Talked to tech at dealership thinking PCM may need to be flashed. Tech says without a CEL they can't do anything did mention he had seen this before and replaced throttle body. I hope it will run long enough to sell. Can't trust it. Thanks for all replies.