Fixed CKP sensor- Importance of checking contact points!

Hello all,
I’m new to this forum and signed up after watching lots of ScannerDanners’ YouTube videos (Thanks Paul!)

I was going to post some questions about testing my CKP sensor the other day after having fits with the P0335 code, sporadic running and long starts and then eventually a no crank condition. My vehicle is a 2014 Silverado with a 5.3 engine.

Well I thought that I could put a new CKP sensor in and fix the problem, but unfortunately it wasn’t that easy. I spent hours trying to access and test wiring and got a good ground and reference circuit test to the sensor but was having a hard time being able to tell what my signal wire was supposed to be doing and couldn’t find parameters for readings so I thought it was good. And on this truck you have to take the starter out to access the CKP sensor and wiring boot(thanks engineers,lol)
Anyways- after replacing the sensor, having the same problem, then pulling my CPS and trying to test that and spending hour online and under the truck, I decided to go back to checking contact points again and look what I found !



That purple wire with the dark blue stripe is the sensor wire for the CKP, and the the other wires were also causing me problems, just not no-start ones.. lol

So this truck has had the fender repaired/ replaced before and the computer sits up in the front driver corner of the fender. Whoever did the body work did not route the lowest trunk wiring harness to the computer correctly and/or didn’t secure it correctly and the trunk was rubbing ever so slightly on the liner of the fender, less than a foot away from the PCM! I wasn’t able to see it from inside but had saw it was touching when I was pulling on the harness from the inside on the hood and got excited as soon as I suspected the problem and sure enough, went down to the wheel well and pulled the lining and saw this... (pictures attached) I had checked the wiring all along the engine because I’ve had the engine rebuilt and thought it could have been a wire routing problem from that (removing the AFM systems, and decided to redo the whole engine), but I didn’t go far enough before I messed with sensors and other tests ! I cut into the harness and spliced the wires and all works well now!

Anyways ! Thought I’d share. Shows that a very thorough wiring check can save you lots of headache, especially when there has been engine or body work before !



-Pierce Vaughn


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