Component Testing

M26 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.
1. Ignition OFF. Disconnect the connector at the front axle engagement actuator.
2. Remove the M26 front axle engagement actuator.
3. 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.
4. 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) .

   • If the M26 front axle engagement actuator DOES perform as described 
5. Refer to Front Axle Will Not Engage , or Front Axle Will Not Disengage .