Have a 2016 GMC 2500HD 4x4 4low works but 4 high doesn't
2 Answers
Feedstoreguy answered 3 years ago
Could have something to do with the actuator motor on the front diff of there is no power to the front wheels in either positions, or if it’s not actuating 4H at the transfer case it could be the motor there as well. Drain the fluid and look for metal shavings. If there is audible loud whirring or grinding you may have a internally damaged transfer case as well. Also don’t rule out switch failure or powertrain computer issues as well.
Feedstoreguy answered 3 years ago
Didn’t mean to end every sentence with “as well”. Maybe I need to get my actuators looked at too