1997 GMC Acadia



December, 16, 2010 AT 5:04 AM

1997 GMC K1500 Truck. I will be driving along in 2wd and it will pop out of 2wd to neutral. I have to pull over and stop to put it in 2wd and continue. What is the problem with the transfer case.


1 Answer



December, 16, 2010 AT 2:01 PM

Perform the following to check if any trouble codes are stored in TCCM.

NOTE: Diagnostic Trouble Codes (DTCs) are displayed on 3 transfer case shift select buttons. When proper conditions are met, select buttons will blink to indicate DTC from "1" to "4".

1. Turn ignition off for at least 6 seconds. Locate DLC near right side of steering column. Install jumper wire between diagnostic pigtail (Orange wire at DLC terminal No. 13) and ground.

2. Turn ignition to run position (engine off). Observe shift select buttons. If all shift select buttons blink once at same time then stop, no DTCs are stored. If only one code is stored in TCCM memory, that code will blink repeatedly, with a 3 second delay between sequences. If more than one code is present, next code will flash after a 3 second delay, then sequence will repeat. Count number of blinks for each code. See Fig. 1.

3. Write down all DTCs. After retrieving DTCs. Clear TCCM memory and repeat procedure. See CLEARING DIAGNOSTIC TROUBLE CODES. If DTCs return, perform appropriate test. See DTC DEFINITIONS under SELF-DIAGNOSTIC SYSTEM.

Please login or register to post a reply.

Drive Shaft Removal - All Cars
Transmission Mount Replacement - RWD Cars
Transmission Fluid Replacement Mercedes Benz
Transmission Turbine Sensor Replacement
Automatic Transmission Service