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Chevy Crankshaft Sensor?

Discussion in 'Truck & Equipment Repair' started by articstorm, Apr 6, 2009.

  1. articstorm

    articstorm Member
    Messages: 31

    I have a 02 Chevy 2500HD with the 8.1 big block and Allison Transmission. Last week I changed the fuel filter and serviced the transmission. When I took it out and drove it shifted hard a couple times and then seemed to clear it's self out. When I brought it home it stalled out. I fired it up and it now runs great for a while and then dies out sporadically and then sometimes it will crank over strong and not want to start at all, and then fire up and run perfect again.

    I should also mention that the check engine light came on on Sunday and after about 25 miles of driving it went away.

    Thinking that it may be related to the new fuel filter somehow, I replaced that again and it still is dying out, usually at idle. I ran it on a friend’s code reader today and it came up with a Code 336 crankshaft position sensor a circuit range/performance, and a Code 1781 Torque signal circuit.

    My first guess was that these code were caused from the transmission shifting problems that I assume were caused from the fluid getting back into all the ports and passages after the fluid replacement, but now I have read some things about the crankshaft position sensor.

    Has anybody had any experience with these sensors or similar problems?
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The '01 and '02 model year 8.1's are well known for crank sensor issues. There was even a TSB on them for it at one point. Swap in the current updated one and you'll be good to go. :salute:
     
  3. articstorm

    articstorm Member
    Messages: 31

    Thanks for the quick response B & B. I ordered the sensor today and will pick it up tonight. I took a look at what I think is the sensor and it looks like it will be a difficult job to do. I'll find out.
     
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Yes they're in a rather difficult to access location. Just take your time and be gentle with it as it is possible to break it while it's still in the block. When that happens the fun stops. :realmad:


    Also, be sure to have a crank relearn procedure done after changing the sensor. This is a worthwhile procedure that re correlates the crank to cam sensor references with the PCM. Should always be done anytime the crank sensor is changed. A dealer or anyone with a GOOD scanner can preform the crank relearn for you. Should be a minimal cost.

    Good luck. :waving:
     
  5. articstorm

    articstorm Member
    Messages: 31

    I started the job last night after I picked up the part and I amazed had how long the sensor was. Total lenght of this part had to be over 8 inched long and most of it goes into the block.

    I decided to stop while I was ahead and took this to the professionals. They had it done today but to late for me to pick it up. They said it was very difficult to get out but they had it done. They said they had a new scanner and they were playing with it on the truck. I didn't ask if they had performed the crank re-learn, but I will ask tomorrow when I pick it up.

    Thanks for the tips B& B. This is a great site with a wealth of knowledge.