DTC indicator light M: A Problem in the Mode Control Linkage, Doors, or Motor

WARNING: This page is about a different car, the 2003 Acura 3.2CL and 2002 Acura 3.2CL. However, it is still accessible from the selected car via links, so may be relevant.

Test the mode control motor (see MODE CONTROL MOTOR TEST ).
Is the mode control motor OK ?
1. YES : Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.
2. NO : Go to step 2.
Remove the mode control motor (see MODE CONTROL MOTOR REPLACEMENT ).
Check the mode control linkage and doors for smooth movement.
Do the mode control linkage and doors move smoothly ?
1. YES : Replace the mode control motor.
2. NO : Repair the mode control linkage and doors.