Operation CHARM: Car repair manuals for everyone.

Improper Air Delivery or No Mode Shift

This procedure provides a test of all functions of the heater/defroster unit.
1. Warm up the vehicle.
2. Keep the engine running.




3. Perform the tests outlined in the table and look for the results indicated.

Steps 1 Thru 14:




Steps 15 Thru 18:




If any of these settings does not produce the correct results, perform the diagnostic procedure.