Test Description
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 heating is insufficient. | ||||||||||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | 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 B0428 or B0429? | -- | 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 operate at the desired speed? | -- | Go to Step 6 | |||||||||
6 | Does the Too Cold In Vehicle concern occur when heat is desired? | -- | Go to Step 7 | Go to Step 8 | ||||||||
7 | Perform the Heating Performance Diagnostic test. Refer to Heating Performance Diagnostic . Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 8 | ||||||||
8 |
Does the scan tool indicate that the value of the Rear Temp.offset parameter changes from the minimum specified value to the maximum specified value? | -4 to 4 | Go to Step 9 | Go to Step 13 | ||||||||
9 |
Does the scan tool indicate that the value of the Rear Temp Dr Actual parameter changes from the minimum specified value to the maximum specified value? | 0-255 counts | Go to Step 10 | Go to Step 15 | ||||||||
10 | Inspect the auxiliary air temperature sensor for the following conditions:
Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 11 | ||||||||
11 |
Does the scan tool indicate that the sensor temperatures are within the specifications at the thermometer temperatures? | -3 to 3°C (-5 to 5°F) | Go to Step 19 | Go to Step 12 | ||||||||
12 | Test the temperature sensor resistance. Refer to Sensor Resistance Table . Does the resistance measure near the Sensor Resistance Table value? | -- | Go to Step 16 | Go to Step 14 | ||||||||
13 | 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 in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 17 | ||||||||
14 | Inspect for poor connections at the harness connector of the auxiliary air temperature sensor. 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 19 | 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 19 | Go to Step 18 | ||||||||
16 | Replace the auxiliary air temperature sensor. Refer to Air Temperature Sensor Replacement - Auxiliary . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||
17 | Replace the auxiliary HVAC control module. Refer to Auxiliary Heater and Air Conditioning Control Module Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||
18 |
Important: Perform the recalibration procedure for the HVAC control module. Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||
19 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 | ||||||||
