Circuit/System Testing

Ignition OFF, disconnect the harness connector at the A16 transfer case motor, also known as the transfer case range actuator.
Ignition ON, engine OFF.

NOTE:

When test probing harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 GM-Approved Terminal Test Kit. Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.
Testing for steps 3-5 is performed on the A16 transfer case motor harness connector using the PU probes J 35616-4A.

Test for 1.0-2.5 V between the transfer case motor counter-clockwise control circuit terminal D and a good ground, such as the ground terminal of the EL-49742 harness, black terminal.
- If less than the specified range
1. Ignition OFF, disconnect the X3 harness connector at the K69 transfer case control module.
2. Test for less than 10 Ω in the transfer case motor counter-clockwise control circuit end to end.
  - If 10 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 10 Ω
3. Test for infinite resistance between transfer case motor counter-clockwise control circuit terminal D and a good ground.
  - If less than infinite resistance, repair the short to ground in the circuit.
  - If infinite resistance
4. Test for greater than 10 Ω between the transfer case motor counter-clockwise control circuit terminal D and all other terminals of the A16 transfer case motor harness connector.
  - If 10 Ω or less, repair the shorted together condition in the affected circuits.
  - If greater than 10 Ω, replace the K69 transfer case control module and perform the Range Actuator Learn procedure.
    Refer to Transfer Case Control Module Replacement , and Transfer Case High/Low Clutch Reset .
- If greater than the specified range
1. Ignition OFF, disconnect the X3 harness connector at the K69 transfer case control module. Ignition ON, Engine OFF.
2. Test for less than 1 V between the transfer case motor counter-clockwise control circuit terminal D and a good ground.
  - If 1 V or greater, repair the short to voltage in the circuit.
  - If less than 1 V
3. Test for greater than 10 Ω between the transfer case motor counter-clockwise control circuit, terminal D and all other terminals of the A16 transfer case motor harness connector.
  - If 10 Ω or less, repair the shorted together condition in the affected circuits.
  - If greater than 10 Ω, replace the K69 transfer case control module and perform the Range Actuator Learn procedure.
    Refer to Transfer Case Control Module Replacement , and Transfer Case High/Low Clutch Reset .
- If within the specified range
Transfer case motor counter-clockwise control circuit and K69 transfer case control module OK.
Test for 3.0-4.5 V between the transfer case motor clockwise control circuit terminal A, and a good ground, such as the ground terminal of the EL-49742 harness, black terminal.
- If less than the specified range
1. Ignition OFF, disconnect the X3 harness connector at the K69 transfer case control module.
2. Test for less than 10 Ω in the transfer case motor clockwise control circuit end to end.
  - If 10 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 10 Ω
3. Test for infinite resistance between transfer case motor clockwise control circuit terminal A and a good ground.
  - If less than infinite resistance, repair the short to ground in the circuit.
  - If infinite resistance
4. Test for greater than 10 Ω between the transfer case motor clockwise control circuit terminal A and all other terminals of the A16 transfer case motor harness connector.
  - If 10 Ω or less, repair the shorted together condition in the affected circuits.
  - If greater than 10, replace the K69 transfer case control module and perform the Range Actuator Learn procedure.
    Refer to Transfer Case Control Module Replacement , and Transfer Case High/Low Clutch Reset .
- If greater than the specified range
1. Ignition OFF, disconnect the X3 harness connector at the K69 transfer case control module. Ignition ON, Engine OFF.
2. Test for less than 1 V between the transfer case motor clockwise control circuit terminal A and a good ground.
  - If 1 V or greater, repair the short to voltage in the circuit.
  - If less than 1 V
3. Test for greater than 10 Ω between the transfer case motor clockwise control circuit, terminal A and all other terminals of the A16 transfer case motor harness connector.
  - If 10 Ω or less, repair the shorted together condition in the affected circuits.
  - If greater than 10 Ω, replace the K69 transfer case control module and perform the Range Actuator Learn procedure.
    Refer to Transfer Case Control Module Replacement , and Transfer Case High/Low Clutch Reset .
- If within the specified range
Transfer case motor counter-clockwise control circuit, transfer case motor clockwise control circuit and K69 transfer case control module OK.