A16 Transfer Case Motor (Transfer Case Range Actuator)

WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, and 2018 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.

Remove the A16 transfer case motor from transfer case. Using a paint pen or marker, place indexing marks on the A16 transfer case motor drive gear and the mounting surface of the A16 transfer case motor.
Attach the red lead from one of the EL-49741 harnesses to the battery positive voltage terminal of the A16 transfer case motor, terminal B.
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 2 - 11 is performed on the A16 transfer case motor harness connector using the PU probes J 35616-5.
Attach the black lead from this same jumper harness to the transfer case lock solenoid control terminal of the A16 transfer case motor, terminal C.
Attach a 9-volt battery to this harness (not included). You should hear the A16 transfer case motor unlock.
- If you do NOT hear the A16 transfer case motor unlock
  Replace the A16 transfer case motor and perform the Range Actuator Learn procedure.
- Go to next step: If you DO hear the A16 transfer case motor unlock
Attach the red lead from the other EL-49741 jumper harness to the transfer case motor clockwise control circuit of the A16 transfer case motor, terminal A.
Attach the black lead from this same jumper harness to the transfer case motor counter-clockwise control circuit of the A16 transfer case motor, terminal D.
Touch the battery terminals of the 9-volt battery to the battery terminals of the jumper harness. This should rotate the A16 transfer case motor drive gear in either a clockwise or counter-clockwise rotation depending on battery orientation.
- If the A16 transfer case motor drive gear does not perform as described
  Replace the A16 transfer case motor and perform the Range Actuator Learn Procedure.
- Go to next step: If The A16 transfer case motor drive gear performs as described
Verify 0.3 - 40 Ω resistance between the transfer case motor clockwise control circuit of the A16 transfer case motor, terminal A and the transfer case motor counter-clockwise control circuit of the A16 transfer case motor, terminal D.
- If NOT 0.3 - 40 Ω
  Replace the A16 transfer case motor and perform the Range Actuator Learn Procedure..
- Go to next step: If 0.3 - 40 Ω
Test for infinite resistance between the following circuits and the A16 transfer case motor case:
- Transfer case motor clockwise control circuit of the A16 transfer case motor, terminal A
- Transfer case motor counter-clockwise control circuit of the A16 transfer case motor, terminal D
- If less than infinite resistance
  Replace the A16 transfer case motor and perform the Range Actuator Learn Procedure.
- Go to next step: If infinite resistance
Test for infinite resistance between the transfer case motor clockwise control circuit of the A16 transfer case motor, terminal A and all other terminals on the A16 transfer case motor harness except the transfer case motor counter-clockwise control circuit of the A16 Transfer Case Motor, terminal D.
- If less than infinite resistance
  Replace the A16 transfer case motor and perform the Range Actuator Learn Procedure..
- Go to next step: If infinite resistance
Test for infinite resistance between the transfer case motor counter-clockwise control circuit of the A16 transfer case motor, terminal D. and all other terminals on the transfer case range actuator harness except the transfer case motor clockwise control circuit of the A16 transfer case motor, terminal A.
- If less than infinite resistance
  Replace the A16 transfer case motor and perform the Range Actuator Learn Procedure.
- Go to next step: If infinite resistance
A16 transfer case motor OK.
Inspect the transfer case shift detent lever shaft for a binding condition.
- If binding
  Remove the transfer case and repair the binding condition. Refer to Transfer Case Shudder or Binding .
- Go to next step: If not binding
Refer to Symptoms - Transfer Case and Front Axle Will Not Disengage .