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Trans went into limp mode (blinking OD light) while towing 6,000 lb trailer, had the code read and, 0603 Check KAPWR To PCM, was the only stored code. I have been fighting this for over a year now and can't figure which way to turn. Trans is rebuilt, ATS TC, The Cure, and Tru-Cool Max and it still happens, but only while towing. I can reset it by pulling the #9 Max fuse and all works good for another 20 miles. I tow in OD except hills, it seems to happen as the trans shift between 3 and OD, even on slight grades like an overpass, I do not let it hunt. While in limp mode the truck dies in reverse, cant back the trailer, TC is locked, until I pull the fuse. What up?
What scanner was used?
Some will not pickup trans codes.
Under those conditions most times its a slip code.
Really need to get the codes out.
The kam error could come from a chip/downloader.
Could be a leak in the TC lockup piston. The higher
line pressure in limp and R could lock the TC.
Just a wag.
What type of scanner do I look for, the one used was at the shop I do all my buisness with, I told them that I was looking for the trans codes and 0603 was what I got back, no other code in there. I was also told that a bad PCM could be the cause for the limp mode.
if it always happens on the 3-4 shift its probably a tc slipping, but as bill said, you need a different scan tool. if it goes to limp mode then there is a code stored
I had it scanned while still in limp mode, I pulled the fuse after the 0603 code was found. Looks like I will have to take the trailer for another tow and have the codes read at a different shop. Thanks for the input, as always it's apreciated.
You should be OBD2.
We need to get the codes out before you do anything.
The OD lamp flashes and you get limp mode so we know its in failure.
Its possible that You lost the kam signal.
In 96 the kam line has a splice in it. (S#126)
Need to remove the connector off of the PCM and test Pin #55.
Its ckt#37 and is a yellow wire. Its 12v 24hr.
I have to go and look up the ground that carries the kam.
Dont have it off hand.
Do this if you are shure that the scan used was good.
If you have power and the grounds it could be the PCM.
Rick or Cuda might be able to post the diagram i cannot.
Excellent!!!
But need the pinout chart also.
Chart shows what the ckt/pin #'s are for.
Pulling fuse 9 tells me Pin 55 should be hot.
Need to check the grounds.
Worth a shot before changing the PCM
Thank for the info Action and Mad. So there is a ground associated with pin 55 that I need to identify and then test the pin to ground and should read 12v? or is testing the ground a different procedure? What is ckt 37?