GM Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
You will want to check the transfer case control module for any trouble codes.
Diagnostic Trouble Code (DTC) Displaying The transfer case shift control module is equipped with the ability to store diagnostic information, which is useful to a technician in the event of a module, component or wiring failure. This information can be retrieved from the transfer case shift control module by way of flash codes, which are displayed on the three transfer case shift control switch buttons. These buttons are located on the instrument panel to the right of the steering wheel. The following steps provide an easy way of retrieving the flash codes properly in the event that a failure has occurred.
Does it still have the code #1?
There may be a problem within the control module.
DTC 1-RAM Standby Power Loss Circuit Description The transfer case shift-control module normally has battery voltage supplied through the battery positive voltage circuit (CKT 40) at all times. When the ignition is ON, the transfer case shift control module conducts a self-test. This self-test determines if the current memory is the same memory that was retained when the ignition was last turned OFF. This self-test indicates whether the RAM standby power-supply to the transfer case shift control module pin C6 was interrupted. If the power is interrupted, the DTCs would be cleared from memory. If the self-test fails, the transfer case shift-control module sets DTC 1.Conditions for Clearing the DTC This DTC will clear when the voltage supply failure has been corrected and the ignition switch has been cycled 5 timesTest Description The numbers below refer to the step numbers on the diagnostic table.
OK I replaced the switch in the dash (control module?). The lights seem much brighter.??? I disconnected the battery for over half an hour. Now when turn on ignition the 4wd light stays on. When I press either of the other two buttons the light flashes and return to 4wd. Now when I ground position 13 data link all the lights flash once about every three seconds as long as I keep grounded. I think we are getting somewhere if only by process of elimination.
PS the CTSY LP fuse was OK
Yeah...that sounds like a code 1, (TCCM) however, the control module is actually behind the right kick panel.
Thanks for your help. The control module ($425.00 list but my little sister got it for me for $306.00) seemed to be the problem. It switches fine from 4wd high and 2wd. It doesn't however seem to want to switch into 4wd low. Any ideas. So far I've changed to switch in the dash, transfer case motor, vacuum sending unit and the control module. I hope that there aren't to many more electrical parts because they are breaking the bank. I can't complain though because the dealer quoted me $1067.00 and I only have a little less than $600.00 in it so far. It seems to drive fine in 2wd and 4wd high and I never have used 4wd low before so it won't break my heart if it doesn't work. Thanks again.