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 below and look for the results indicated.

Steps 1 - 14:

Steps 15 - 18:

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