The numbers below refer to the step numbers on the diagnostic table.
The test lamp should illuminate while trying to command the appropriate mode door in both directions.
Two ignition 3 voltage circuits supply the HVAC control module. Test the ignition 3 voltage circuit that does not supply the blower motor switch.
Check the connection by removing and securely reinstalling before replacement of the HVAC control is considered.
Step | Action | Yes | No | ||||||||||
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Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: Air does not flow correctly from the air distribution outlets. | |||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||||||
2 |
Is the blower motor OFF? | Go to Step 3 | Go to Blower Motor Always On | ||||||||||
3 | Place the blower motor switch in each speed position. Does the blower motor operate in any speed position? | Go to Step 4 | Go to Blower Motor Inoperative | ||||||||||
4 | Does the blower motor operate in each speed position? | Go to Step 5 | Go to Blower Motor Malfunction | ||||||||||
5 | Are all of the HVAC control module controls except for the blower motor inoperative? | Go to Step 15 | Go to Step 6 | ||||||||||
6 |
Does the recirculation door move from the recirculation to the outside air position? | Go to Step 7 | |||||||||||
7 |
Does air flow sufficiently from the proper air distribution outlets for each selected mode position? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 8 | ||||||||||
8 | Inspect the air delivery system for the following conditions:
Did you find and correct the condition? | Go to Step 21 | Go to Step 9 | ||||||||||
9 | Inspect the appropriate mode door and the mode actuator for the following conditions:
Did you find and correct the condition? | Go to Step 21 | Go to Step 10 | ||||||||||
10 | Test the position signal circuit of the appropriate mode actuator for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 11 | ||||||||||
11 | Test the low reference circuit of the appropriate mode actuator for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 12 | ||||||||||
12 | Test the 5-volt reference circuit of the appropriate mode actuator for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 13 | ||||||||||
Does the test lamp illuminate in both positions? | Go to Step 17 | Go to Step 14 | |||||||||||
14 | Test the mode door control A and mode door control B circuits of the appropriate mode actuator for an open, a high resistance, a short to ground, or a short to voltage. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 18 | ||||||||||
Test the ignition 3 voltage circuit of the HVAC control module for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 16 | |||||||||||
16 | Test the ground circuit of the HVAC control module for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 18 | ||||||||||
17 | Inspect for bad connections at the harness connector of the appropriate mode actuator. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 19 | ||||||||||
Inspect for bad connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 20 | |||||||||||
19 | Replace the appropriate mode actuator. Refer to Panel Actuator Replacement or Defroster Valve Actuator Replacement or Floor Air Valve Actuator Replacement . Did you complete the replacement? | Go to Step 21 | -- | ||||||||||
20 | Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 21 | -- | ||||||||||
21 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 8 |