P0335 - crankshaft position sensor issues… sos

[Marknbacon]

Hello folks, so I’m currently dealing with an issue on my 2015 SS. Full story is as follows:

Started with slow starting followed by TC and Stability control lights staying on. Read codes and had a P0336. Turned off, cleared codes, started back up and same issue but also with P0335 in addition to 36 at same time. Drove it home and noticed decreased throttle response as well as some rattling/ticking with sudden throttle more than about 50% throttle also had some backfiring. Did a little research and it made sense that the Crank position sensor was going out. Bought a new one from orileys, slapped it in (honestly it’s not that bad of an install, probably harder than it needs to be since I have headers but still only about an hour start to finish) and boom no more sluggish cranking or codes. Good for about two or three months… then started having same issue but this time with only P0335 code. Tried a few cycles of clearing and starting and still had same issue. But the bullet and bought a GM parts direct replacement that allegedly matched that car.

Here we are about 3 weeks later and I’m having the same problem.

I believe that there is another issue going on here other than just crappy parts.

Not 100% sure how to troubleshoot this issue but I’m trying to figure it out.

I have ordered a replacement pigtail for the sensor. The way the wires go into the connector isn’t bringing me joy (hard angles and very tightly wrapped with electrical tape) so I’m thinking there may be a wiring problem but I’m not sure.

Thoughts? Ideas? Anyone had this issue before?


Sent from my iPhone using Tapatalk

[gtstorey]

"Common causes of the P0335 code code are a bad crankshaft position sensor, failed reluctor ring, circuit issues, and PCM problems."

No way to guess which one it is. OEM service manual will have diagnostic steps for the code, but usually not for a beginner. And if installing a pigtail is not within your skill set, you probably need to find a good diagnostic mechanic.

[Marknbacon]

Originally Posted by gtstorey

"Common causes of the P0335 code code are a bad crankshaft position sensor, failed reluctor ring, circuit issues, and PCM problems."

No way to guess which one it is. OEM service manual will have diagnostic steps for the code, but usually not for a beginner. And if installing a pigtail is not within your skill set, you probably need to find a good diagnostic mechanic.

Alright, so if it makes a difference, it seems that the car is happy with a new sensor for a while... which makes me think there is a bad wire that is allowing some current to pass and a brand new sensor is producing a good signal, while as it is run the sensor is somehow being "broken in" (perhaps expansion and shrinkage from heat?) and after a while it is not producing a strong enough return signal (due to voltage drop through a bad spot of wire) to tell the ECM where the crank is (below the logic high threshold probably, assuming the point is for the reluctor wheel to generate essentially a digital pulse through the hall effect crankshaft position sensor) Which in my opinion would explain why it starts doing it gradually.

Yeah I have enough knowhow to change a pigtail.... and a lot of other things, just getting the troubleshooting steps down is challenging.

That being said, I'm going to rule out everything else before we go diving into the world of changing a reluctor ring... Will probably have to take to a mechanic for that. Not that I don't think I could do it myself, I just don't have all the tools to essentially rebuild the bottom end of the motor, plus I would want to go ahead and beef the bottom end up while I'm in there. I also don't have 7k laying around for this purpose. (that's what I was quoted from the local "go-to" LS guy)

Do you have a copy of those steps from the manual? If you do, can I get a copy of those steps? That would be very helpful I believe.

[gtstorey]

ac delco tds subscription

or

alldata.com

[Marknbacon]

Originally Posted by gtstorey

ac delco tds subscription

or

alldata.com

Gotcha. I may have to bite the bullet on that. Been thinking about all data for a while as I always seem to end up needing more than Haynes can provide.

Update: attempted a bench test on the old ones but couldn’t get them to respond, tried new sensor and same deal… ohmed out wires from sensor to ECM (X2 connector which is the 80 pin, which is closest to the back of the engine bay compared to the x1. On my car it was pins 2, 68, and 69) and got .4 ohms on each conductor, wiggled the connector and the wires while I tested each one and the meter didn’t even flinch…
Put car back together with new oriley sensor and it fired right up like it’s supposed to. Test drove it and it worked how it’s supposed to… ECT and oil temp within normal range the whole time….
Bruh, I am so confused right now lol. Could I be the victim of two defective sensors in a row? That seems really unlikely but idk. We will see over the next few weeks.

Oh, I also took a peek at the reluctor wheel with my inspection camera, and it looks fine.


Sent from my iPhone using Tapatalk

[Mouse330]

You really need a good scanner for the diagnostics on this, You would need to verify The crankshaft position active counter parameter increments with the engine running. The crankshaft position resync counter parameter engine running. Then you would need to get into circuit testing i.e. ohms testing between the ECM and the CKP. KOEO there should be a 5V reference on pin "C" PU/WH wire at CKP, Ground on "B" GR/BK, "A" WH/BK is the CKP signal circuit.