Operation CHARM: Car repair manuals for everyone.

Improper Air Delivery or No Mode Shift

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 above and look for the results indicated.

Step 1 - 9:




Step 10 - 18:




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