The numbers below refer to the step numbers on the diagnostic table.
The specified values are from the A/C System Performance Test.
The voltage will vary between 0-12 volts during normal operation. The HVAC control module connector must be connected during this step.
Step | Action | Values | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics Definition: The temperature cannot be adjusted, or the cooling is insufficient during A/C operation. | ||||||||||||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | |||||||||||
2 |
Does the blower motor operate correctly for each speed position? | -- | Go to Step 3 | Go to Blower Motor Inoperative | ||||||||||
3 | Does the blower motor provide sufficient air flow? | -- | Go to Step 4 | Go to Blower Motor Malfunction | ||||||||||
4 |
Does the recirculation door operate properly? | -- | Go to Step 5 | |||||||||||
5 | Does the Too Hot in Vehicle concern occur when A/C cooling is desired? | -- | Go to Step 6 | Go to Step 8 | ||||||||||
6 |
IMPORTANT:: For A/C compressor operation, ambient air temperature must be above 3°C (38°F).
Does the A/C compressor operate? | -- | Go to Step 7 | |||||||||||
Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test in Heating, Ventilation and Air Conditioning. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 8 | |||||||||||
8 |
Does the air temperature actuator drive shaft rotate at all? | -- | Go to Step 9 | Go to Step 10 | ||||||||||
9 | Inspect the air temperature door and the air temperature actuator for the following conditions:
Did you find and correct the condition? | -- | Go to Step 18 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | ||||||||||
10 | Test the ignition 3 voltage circuit of the air temperature actuator for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 11 | ||||||||||
11 | Test the ground circuit of the air temperature actuator for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 12 | ||||||||||
12 | Test the air temperature door position signal circuit of the air temperature actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 13 | ||||||||||
Important: Ensure that the HVAC control module connector is connected during this step in order to avoid misdiagnosis.
Does the voltage measure within the specified values with a smooth transition between cold and hot? | 12 V at cold 0 V at hot | Go to Step 15 | Go to Step 14 | |||||||||||
14 | Inspect for poor connections at the harness connector of the air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 16 | ||||||||||
15 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 17 | ||||||||||
16 | Replace the air temperature actuator. Refer to Air Temperature Actuator Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||||||
17 | Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||||||
18 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |