Engine codes

[Mhyd]

I need some help. I have racked my brain for a week now trying to figure this out I have a p0340 p0341 p0335 codes that came up on my truck. It is a 2018 Silverado haven’t had any issues out of the truck but with I went to the car wash on Monday it was fine Tuesday got in it to go to work and felt like a brake was grabbing when the traction control comes on. It was not the case then 5 miles later the engine codes come on. I have replaced cam and crank sensors and the negative battery cable as I was told by the dealer that was the issue well it is currently still doing the same thing and has an extended crank when starting. I have checked grounds everywhere but can’t find anything wrong just asking if anyone else has had this issue and there is zero reason to believe it’s motor cause it sounds perfect.

[CamGTP]

If you replaced both sensors and checked all grounds then you left with checking the wiring harness for damage. It's not going to be fun but you need to trace the wires back through the harness to see if there are issues. You can also find a wiring diagram to test the wires from the fuse block or PCM back the sensor itself to make sure you have a good wire all the way through.

[Mhyd]

Thank you I will start this afternoon crawling around looking for something I appreciate your help

[Mhyd]

Still having the same issue after checking the grounds

[mikeyk101]

3 hours ago, Mhyd said:

Still having the same issue after checking the grounds

 

You don't mention which grounds you checked. There are multiple grounds on these trucks. They each need to be inspected and cleaned up. Frame to body, engine to firewall, etc...

[rlcole321]

There could be a cam timing issue, if the cam and crankshaft get too far out of alignment, say stretched chain or bad chain tensioner, or bad VVT phaser, this could be the cause. If your wiring checks out, then look into that.

[Mhyd]

Still no luck with finding what’s wrong with it one dealership said the ecm could be out cause on a scanner it’s not reading anything out of the cam sensor but has 5v going to it and ground wire is fine. I did fill it up with gas shut it off went to start it back would not start said reduce engine power let it set for a little bit and started right up so I’m at a loss

[wunsch2]

On 3/17/2025 at 3:07 AM, Mhyd said:

Still no luck with finding what’s wrong with it one dealership said the ecm could be out cause on a scanner it’s not reading anything out of the cam sensor but has 5v going to it and ground wire is fine. I did fill it up with gas shut it off went to start it back would not start said reduce engine power let it set for a little bit and started right up so I’m at a loss

Have you tried checking the cam sensor connections and wires? I have had similar issues and sometimes just cleaning the connections or rechecking the wiring fixes the problem.

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Edited August 14, 2025 by wunsch2