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Test Description

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The number(s) below refer to the step number(s) on the diagnostic table.

  1. 5. Test the HVAC control module front defrost button and the mode button for proper operation.
  2. 6. Can you hear the recirculation door switch from outside air to the recirculation position.
  3. 8. Tests the HVAC control module for the proper commanded state. The ON/OFF positions for each mode are as follows:

    FLOOR POSITION - solenoids 1 and 5 OFF, solenoids 2 and 3 ON, solenoid 4 ON or OFF.

    VENT POSITION - solenoids 1 and 3 OFF, solenoids 2 and 5 ON, solenoid 4 ON or OFF. VENT/FLOOR POSITION - solenoids 1, 3 and 5 OFF, solenoid 2 ON, solenoid 4 ON or OFF.

    FLOOR/DEFROST POSITION - solenoids 1, 2, 4 and 5 OFF and solenoid 3 ON.

    DEFROST POSITION - solenoids 1 and 3 ON and solenoids 2, 4 and 5 OFF.

  4. Tests the solenoid circuits for an open or short.
  5. Tests the solenoid circuits for an open or short.
  6. Tests the vacuum control assembly solenoids.
  7. Tests for a constant ground, constant voltage and an open on the solenoid control circuits.
    Fig 1: Diagnostic System Check Table (Air Delivery Improper) (Step 1-7)
    G01418945Courtesy of GENERAL MOTORS CORP.
Fig 2: Diagnostic System Check Table (Air Delivery Improper) (Step 8-19)
G01418946Courtesy of GENERAL MOTORS CORP.
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