Transfer case control module

BLCKLBRTRVR

MEMBER
2006 GMC SIERRA
5.3L
V8
4WD
AUTOMATIC
250,000 MILES

When checking for 5vlt at signal wire (Lt grn/blck + blk/wht)at female end of harness at encoder motor. I don't get a reading until I put one lead to the frame. Same happens when I check return signal with jumper.

I check all wires from module to encoder motor and from engine to module for ohms, nothing over.2. I checked voltage at module I had 5.06 volts at signal wire same as above. I had 12.5 volt for battery.

Do you think the tcc module is bad at the blck/wht (encoder low reference) wirer?

8 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good evening,

I attached a wiring diagram for you to view. It is a 3 wire connector. You should have reference voltage on both the reference and the signal wire from the module.

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

The return wire is the ground controlled by the module.

Can you verify these voltages?

Roy

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Tuesday, December 22nd, 2020 AT 3:08 PM

BLCKLBRTRVR

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I had at the module 5.06 volts for signal wire and 5.06 volts for return signal but when I plugged the harness into module and tested from the end of harness near encoder. I get nothing. When I test same wirers from engine side I had 5.06 volts.

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Tuesday, December 22nd, 2020 AT 6:26 PM

BLCKLBRTRVR

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9 POSTS

If I try to get volt reading from black/white encoder low reference on harness with dvm - an dvm + on 5 volt reference light green/black and same for dvm + brown/white encoder signal I get.1
But I get the right readings for all other wire on harness using dvm - on encoder low reference black/white an dvm + on other wires. So confused.

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Tuesday, December 22nd, 2020 AT 7:12 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

Based on your results you need the module.

Roy

Transfer Case Shift Control Module Replacement

Removal Procedure

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1. Disconnect the shift control module electrical connectors.

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2. Unsnap and remove the shift control module from the bracket.

Installation Procedure

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1. If a new control module is being installed, program the new module. Refer to Control Module References in Computer/Integrating Systems. See: Vehicle > Programming and Relearning
2. Install the shift control module to the bracket.

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3. Connect the shift control module electrical connectors.
4. Start the engine and test the automatic transfer case system for proper shift operation.

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Wednesday, December 23rd, 2020 AT 3:04 AM

BLCKLBRTRVR

MEMBER
9 POSTS

I tested the module it's okay values are good. But if I reconnect harness and measure at encoder connector female side of harness I'm not getting the right readings from encoder signal, low reference and 5 volt reference. This is where I get on fused. Thinking I need to do a voltage drop test on those three wirers? When I test at connection in engine compartment of same three wire I think coming from module I get correct value.