Transfer case encode motor short to ground or open

2006 GMC SIERRA

250,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC

BLCKLBRTRVR

MEMBER
9 POSTS
FOLLOW

With key on using dmm with actuator unplugged and dmm one end ground to frame and other lead on (a) grrrn/black I get 5.06 volts when I touch (b) I get 23.5volts. What is (b) value telling me a bad wire or TCCM bad? (C) value 1.4 volts (d) 1.8 (e) 2.1 and fluctuating (f)12 volts (g) 2.0 Are these values in ranges?

Bryant

Dec 20, 2020 at 5:09 PM

KASEKENNY

CERTIFIED EXPERT
18,907 POSTS

I am attaching the wiring diagram. A is your 5 volt reference so that is correct. However, B is you encoder signal return and it should run through a resistor in the encoder so I suspect the encoder has failed. I have not seen the voltage be that high but that is the only thing at this point that would make sense. I would suggest unplugging the encoder and the shift module and check for a short on the wire and if none is found then it is the encoder.

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-wiring

I also attached below the process to replace the encoder if this proves out. Thanks

Images (Click to enlarge)

Dec 21, 2020 at 6:18 PM