Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This test resets the HVAC control module and checks for current air temperature actuator DTC.
-
The specified values are from the A/C System Performance Test.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The auxiliary air temperature cannot be adjusted from one or both auxiliary controls, or the auxiliary cooling is insufficient. | ||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||
2 | The auxiliary HVAC control module cannot request A/C compressor operation. An A/C request must be generated by the HVAC control module to provide cooled airflow through the auxiliary system. Does the HVAC control module operate and provide sufficient heating? | -- | Go to Step 3 | Go to Too Cold in Vehicle | ||||||||
Does the scan tool display DTC B0433? | -- | Go to Step 4 | ||||||||||
4 | Place the auxiliary blower motor switch in each speed position. Does the auxiliary blower motor operate in each speed position? | -- | Go to Step 5 | |||||||||
5 | Does the auxiliary blower motor operate at the desired speeds? | -- | Go to Step 6 | |||||||||
6 | Does the Too Hot In Vehicle concern occur when A/C is desired? | -- | Go to Step 7 | Go to Step 8 | ||||||||
Perform the A/C system performance test. Refer to Air Conditioning (A/C) System Performance Test . Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 8 | |||||||||
8 |
Does the value measured stay within the specified range with a smooth transition between cold and hot? | 0-255 Counts | Go to Step 9 | Go to Step 14 | ||||||||
9 | Inspect the air temperature sensor for the following conditions:
Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 10 | ||||||||
10 |
Does the scan tool indicate that the sensor temperatures are within the specification at the thermometer temperatures? | -3 to +3°C (-5 to +5°F) | Go to Step 18 | Go to Step 10 | ||||||||
11 | Test the temperature sensor resistance. Refer to Sensor Resistance Table . Does the resistance measure near the Sensor Resistance Table value? | -- | Go to Step 15 | Go to Step 13 | ||||||||
12 | Inspect for poor connections at the harness connector of the auxiliary HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 16 | ||||||||
13 | Inspect for poor connections at the harness connector of the upper duct temp sensor, and lower duct temp sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 15 | ||||||||
14 | 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 . Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 17 | ||||||||
15 | Replace upper duct temp sensor or lower duct temp sensor. Refer to Duct Air Temperature Sensor Replacement - Upper Right Side , Duct Air Temperature Sensor Replacement - Upper Left Side , Duct Air Temperature Sensor Replacement - Lower Left Side , or Duct Air Temperature Sensor Replacement - Lower Right Side . Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||||
16 | Replace the auxiliary HVAC control module. Refer to Control Module References for Auxiliary HVAC replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||||
17 | Replace the HVAC control module. Refer to Control Module References for HVAC replacement, setup, and programming. 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 | ||||||||
