M26 Front Axle Engagement 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.

Ignition OFF. Disconnect the connector at the front axle engagement actuator.
NOTE:
- Circuit/System Testing must be performed before Component Testing.
- 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 - 4 is performed on the M26 front axle engagement actuator harness connector using the BL probes J-35616-65B.
Remove the M26 front axle engagement actuator.
Connect the M26 front axle engagement actuator connector. Position the M26 front axle engagement actuator so that it is visible from the side of the vehicle.
Using the Front Axle Engagement Actuator control function of the scan tool, command the front axle to engage and disengage. When commanded to engage, the plunger on the M26 front axle engagement actuator should extend. When commanded to disengage, the plunger should retract.
- If the M26 front axle engagement actuator does NOT perform as described
  replace the M26 front axle engagement actuator. Refer to Front Drive Axle Actuator Replacement (8.25 Inch LD Axle)Front Drive Axle Actuator Replacement (9.25 Inch HD Axle) .
- Go to next step: If the M26 front axle engagement actuator DOES perform as described
Refer to Front Axle Will Not Engage or Front Axle Will Not Disengage .