P1336...but worse
11-19-2014, 09:58 PM
#1
P1336...but worse
last month, i did a PCM swap to have my tune corrected for the new 4.30s in installed. i was a little hasty & had Justin send me a new PCM so i didn't have down time waiting on mine to ship out & come back (i was expecting to deploy at the end of last month... which, of course, didn't happen). the thing i forgot was that it often needs a crank relearn. well, what'dda ya know? i put the computer in & it fires right up & runs fine!
i took it about .5mi down the road & back to verify that the speedo/tach were right now. everything was fine except for the CEL. i left it alone for the night, but the next day after i changed the gear oil, i took it 10min down the road to AutoZone to get the code read. on this drive, i started to feel it hesitate some. i got there & they pulled a P1336 (needs a crank relearn). i started home & made it to the 1st light - then it flat died. it would crank over & run maybe 3-4 seconds total & die again. after a few tries with no luck, i ended up getting a ride home to grab the old computer.
here's where it gets messed up - i swapped the old PCM in & it did the same thing. long story short, after a few tries of swapping computers back & forth & having the same run-then-die after 3-4 seconds problem, i trailered it to the dealer to get a TechII CASE relearn. they couldn't get it to run long enough to do the procedure (granted, i can't be sure they knew all about it, but they claimed to be familiar with the process). it actually got worse - as in now it won't fire at all... it just turns over.
any clues as to what might be going on here?
i initially thought it might be a VATS thing, but i never had a SECURITY message. also, would the new PCM cause the old one to lose its crank sensor calibration? without a datalog of what's going on, me & the tuner are at a loss for ideas now.
of course, i had to go TDY right in the middle of this, so it's been sitting in the dealership parking lot for 2 weeks now (and i heard today that they just moved to their new location - so it's just in an abandoned lot now!). on top of that, the snow finally hit town, so i get to plow the vette through that when i get back until this mess gets sorted out! fun times, right?
on the bright side, i did just order an OBDII interface that should be there when i get home so i can get a log of what it's doing.
i took it about .5mi down the road & back to verify that the speedo/tach were right now. everything was fine except for the CEL. i left it alone for the night, but the next day after i changed the gear oil, i took it 10min down the road to AutoZone to get the code read. on this drive, i started to feel it hesitate some. i got there & they pulled a P1336 (needs a crank relearn). i started home & made it to the 1st light - then it flat died. it would crank over & run maybe 3-4 seconds total & die again. after a few tries with no luck, i ended up getting a ride home to grab the old computer.
here's where it gets messed up - i swapped the old PCM in & it did the same thing. long story short, after a few tries of swapping computers back & forth & having the same run-then-die after 3-4 seconds problem, i trailered it to the dealer to get a TechII CASE relearn. they couldn't get it to run long enough to do the procedure (granted, i can't be sure they knew all about it, but they claimed to be familiar with the process). it actually got worse - as in now it won't fire at all... it just turns over.
any clues as to what might be going on here?
i initially thought it might be a VATS thing, but i never had a SECURITY message. also, would the new PCM cause the old one to lose its crank sensor calibration? without a datalog of what's going on, me & the tuner are at a loss for ideas now.
of course, i had to go TDY right in the middle of this, so it's been sitting in the dealership parking lot for 2 weeks now (and i heard today that they just moved to their new location - so it's just in an abandoned lot now!). on top of that, the snow finally hit town, so i get to plow the vette through that when i get back until this mess gets sorted out! fun times, right?
on the bright side, i did just order an OBDII interface that should be there when i get home so i can get a log of what it's doing.
11-21-2014, 09:31 PM
#3
Vehicle needs to run in order to do a crank relearn.
Maybe a pin backed out on the harness.
Only time I saw an issue like this we had to replace the BCM and Lock Cylinder.
I wanted to try and remove the Vats to see if it would start but it wasn't my call or money...
Maybe a pin backed out on the harness.
Only time I saw an issue like this we had to replace the BCM and Lock Cylinder.
I wanted to try and remove the Vats to see if it would start but it wasn't my call or money...
11-21-2014, 11:06 PM
#4
has anybody used ScanXL to datalog or read DTCs? is it a decent program?
do you think if i cleared the P1336 out, it would maybe try to run at least long enough to accomplish a relearn?
and i looked at the pins on the PCM, and they were fine. i'll have to give the harness a thorough scan to see if any females pushed up in there.
what would cause the BCM to be affected by this? from what i understand, VATS was disabled in the tune, and i never once got the SECURITY message. the same original key worked with the old computer & the new one, so i doubt it's an issue with the lock cylinder.
do you think if i cleared the P1336 out, it would maybe try to run at least long enough to accomplish a relearn?
and i looked at the pins on the PCM, and they were fine. i'll have to give the harness a thorough scan to see if any females pushed up in there.
what would cause the BCM to be affected by this? from what i understand, VATS was disabled in the tune, and i never once got the SECURITY message. the same original key worked with the old computer & the new one, so i doubt it's an issue with the lock cylinder.
11-22-2014, 12:17 AM
#5
I have not used it.
Most likely clearing the code will not allow it to start. I would put the original PCM and try to get it running again. It should at least run even though the gear ratio isn't correct,
Look at the pins on the PCM connector and make sure they are not backed out. Also check your Ground's to the block and the chassis.
Put the battery on a slow charge overnight. I just purchased a new one that cycles back and forth and maintains the battery once it's fully charged.
For reference, what year is the truck???
Most likely clearing the code will not allow it to start. I would put the original PCM and try to get it running again. It should at least run even though the gear ratio isn't correct,
Look at the pins on the PCM connector and make sure they are not backed out. Also check your Ground's to the block and the chassis.
Put the battery on a slow charge overnight. I just purchased a new one that cycles back and forth and maintains the battery once it's fully charged.
For reference, what year is the truck???
11-22-2014, 12:28 AM
#6
Oh, we were never able to get the truck running. He supposedly knew someone at a dealership. Long Story short, $750 later supposedly it needed a new BCM and there was an issue with Key cylinder housing. Of course they wouldn't let me speak directly to the tech about it...
11-22-2014, 01:20 AM
#7
it's a 99 Sierra 1500 with a 2001 LM7 5.3. tuned on a 411 PCM with the red/blue connectors. the first thing i did was try to drive it home on the old computer, but the problem is that neither the old or new ones work now - they're BOTH doing the turn-over, no-fire thing. that was after driving 3.5yrs on the old PCM without an issue (even after a mail-in reflash early last year). and on top of that, the new one drove for a couple days before acting up.
what i'm trying to figure out is not only how to get it running again, but also what caused the old computer to suddenly not work either.
what i'm trying to figure out is not only how to get it running again, but also what caused the old computer to suddenly not work either.
