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Hey guys,
Quick question, or at least I hope.
My truck has the push button transfer case selector. Sometimes when I start the truck it shows to be in neutral. the red led is lit. I press 2 wheel drive and put the truck in neutral and everything seems O.K. from there.
Any suggestions? This has been going on for sometime now.
Thanks in advanced.
First, try a reset of the transfer case control module. Set the E-brake or chock the wheels. Key on, then remove the ATCM/TREC fuse under the hood. Replace it in a minute or so. The switch LED's should flash some sequence, then indicate correctly. If you have a capable code scanner, check for "C" codes in history. C0550 indicates a communication loss with the TCCM.
The switch is not without historical issues. Mine failed within weeks of brand new (the truck), then again a decade later, and now the LED's have a mind of their own (the switch works fine, but I have to guess what the LED's should indicate). The next time it happens, verify the state of the TC (determine if, in fact, it is in neutral, before pressing any buttons). If the TC is in Neutral and the E-brake isn't set, the truck will roll, so that may present a hazard. I suspect the problem is likely the LED's. Shifting the TC into Neutral is a process, and specific conditions must be met. It's also noisy, in that you can hear the steppers operate, and hear the clunk of the shift. Fortunately, the switches are not expensive, and very simple to replace (~10 minutes). Remove instrument panel bezel (pops off), release the switch (lock tabs and maybe a screw, don't recall), disconnect, replace in reverse order. The headlamp switch R/R is the same.
If the switch is not the problem, and/or the TC is actually shifting to Neutral, it's likely the Transfer Case Control Module (behind the dash, on the steering column, or behind the left-knee panel). It can be reprogrammed with a Tech II and GM calibration code (rarely successful, but a first step), or replaced. They are not inexpensive, and new may require programming (it's better to source a good used module from a like truck, which will just work).
Much appreciate the info!!!
Thank you Sir!
I paid about $100 for the used TCCM I found for Lil Red back in 2004. I bought all of the various used modules (TCCM, BCM, TCM, ECM, etc) at the same time... I doubt they were all from the same truck. None of them required reprogramming, but I had read at the time that it might be necessary.Quote:
Originally Posted by DmaxMaverick