P0335 (crank pos sensor) issue

[ls1frc]

Hey all, I have been having issues with my 2012 6.2 swapped Yukon since I got it back together after a head gasket repair. It was fine for a hundred miles or so, but I got on it hard the other day and it's been having this issue ever since.

It is sporadically throwing a p0335 code which leads to the truck running like crap, the tach going to 0, and the tcs/stabiltrak lights coming on. It's weird though because it does it way less after I swapped in my old battery I had laying around. I thought I fixed it with the battery swap, so I got a new platinum AGM battery and put that in, and it did it even worse.

I checked the grounds on the back of the driver side head, the front of the passenger side head, and the ground wire under the front cross member for the negative battery.

Tomorrow I am going to just replace the crank sensor since I believe another ground wire is tucked away near it somewhere on the block, so it will allow me to inspect that.

I wanted to post here though in case someone else had a similar issue. I am really bummed about it because I just got the truck back together and was looking forward to taking road trips again. I was looking at used prices for this generation and was shocked at how inflated they are....

 

[ls1frc]

Have this feeling it's still battery related. I wonder if it is just the negative cable

 

[strutaeng]

Could be the sensor for sure if tach drops to zero. Don't you have to do a crank relearn?

 

[ls1frc]

Could be the sensor for sure if tach drops to zero. Don't you have to do a crank relearn?

Not sure, if so I do have hptuners

 

[Fless]

Not sure where yours is, but maybe shim or no shim?

 

[strutaeng]

Shim or no shim?

That's on the SBC-based 4.3, I believe he said. Crank sensor definitely looks like a 4.3 and he mentions it goes in the timing cover underneath.

Never heard of installing a shim on the LS-based V8...does it apply also? I have heard of reluctor getting bent when installing the crank on an engine rebuild though.

 

[Fless]

That's on the SBC-based 4.3, I believe he said. Crank sensor definitely looks like a 4.3 and he mentions it goes in the timing cover underneath.

Never heard of installing a shim on the LS-based V8...does it apply also? I have heard of reluctor getting bent when installing the crank on an engine rebuild though.

I'm not sure, as I'm not familiar with the newer engines. Probably doesn't apply to the LS V-8.

 

[ls1frc]

Update...

Replaced the negative battery terminal/ground cable wire and put back in the *new* battery. As soon as I floored the pedal on my test drive, the car sputtered, tachometer went to 0 and I saw the p0335 code again. I put in my old battery from my C7 corvette, and took it for another test drive. This time the truck ran fine and I was able to go wot all the way to about 80 with no issues.

I think the battery is masking a deeper issue though since I still had the issue with the previous battery of the same type (advance auto platinum AGM battery).

I am not sure where to go next with my troubleshooting. I have a new GM crank pos sensor and a new pigtail. I also have a new positive battery terminal.

 

[ls1frc]

Okay so it started doing it with the other battery now. One of the wires must be moving in a way when I swap batteries, causing the issue to go away momentarily. There's a positive wire to the starter, a ground wire, and the crank pos sensor wiring that are bunched up together. I'll inspect all of that soon.

 

[j91z28d1]

just a thought, and I don't know that it would help in the trouble shooting any, but can you pull the big wire off the alt, tape it up some it doesn't short out. so the truck is turning just off the battery and see if it dies out when you wiggle the battery cables or something?

 

[ls1frc]

I think you’re onto something

The truck just left me stranded. Completely dead would not turn over. My noco jumper got it started and I made it five miles before it died again. I got all sorts of codes like camshaft position sensor etc. so I don’t think this has any relation to any sensor

I went home, got the other battery, swapped it in and the truck started right up. I think when I bend the cable back to put the battery in something must be temporarily reconnecting. I have two out of the three red cables that go onto the battery. The one to the starter and the one to the alternator. I’m going to replace the one to the alternator now since I don’t have time to pull the header to get to the starter

 

[j91z28d1]

it's worth changing them all, but if you have to do just one and can get to it. I'd change the ground cable.


also just as a FYI, the terminals in the battery posts should be tight. like can't twist them at all with 2 hands tight. loose terminals are a issue that pop up here from time to time. guys just done realize how tight they need to be unless you fight with on the daily.

 

[ls1frc]

I did the ground cable yesterday did not resolve it

I’ll crank down on them after I replace the red ones

 

[petethepug]

As a baseline replace both the +\~ cables as they corrode internally causing random DTC. Also pull & replace the carbon canister under the truck if not done yet to verify no carbon pellets are in the fuel system. Problems occurring when the tank is less than 1/2 full could point to fuelling issues.

Glad to hear you’ve had a few successful full pulls on the new motor though. You’re close.

 

[Geotrash]

I'll add my +1 to the chorus saying it's a battery connectivity issue. When the GMC dealer did my airbag recall last year, they forgot to tighten down the terminals on the battery. The engine quit and everything went dark just as I was pulling out into traffic. I drifted back into the road I was pulling out of, grabbed a 10mm wrench from my tool bag and snugged them up. No problems since, but the service manager got an earful.

Long story short, a bad or loose battery cable on either side will cause the engine to quit.

 

[ls1frc]

Okay I am going out to the truck to replace two of the three red cables. The third cable is the one that runs along the back of the engine bay and into the PCM. That I do not have a replacement for yet

I am thinking all this isn't really related to the crank pos sensor since I got different codes now. I may replace it anyway since getting there is annoying since I have to drop the header and the starter.

 

[ls1frc]

Found an issue not sure if it’s THE issue. But the wire to the starter was loose. And what I thought was a lock washer appears to just be a broken washer.

 

[ls1frc]

Anyone know if I can use any old washer or do I need the gm part?

I haven't seen any GM parts that match this, seems to just come with a new starter. I am just not sure if I can use any old washer or it has to be something specific.

I'll hit up napa tomorrow and see

 

[ls1frc]

I am thinking this has to be my issue...

I did throw in the new crank sensor just because I was down there

 

[Geotrash]

Anyone know if I can use any old washer or do I need the gm part?

I haven't seen any GM parts that match this, seems to just come with a new starter. I am just not sure if I can use any old washer or it has to be something specific.

I'll hit up napa tomorrow and see

It’s probably made of copper. I have a full set of copper washers from horrible freight, so you could swing by there if needed.