Test Description
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
The number below refers to the step number on the diagnostic table.
- 12: The voltage will vary between 0-12 volts during normal operation. The HVAC control module connector must be connected during this step.
Too Cold in Vehicle
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The temperature cannot be adjusted or the heating is insufficient. |
||||
| 1 |
IMPORTANT:
Both the left and the right air temperature controls are diagnosed in this table. Did you perform the Diagnostic System Check - Vehicle? |
- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 |
|
- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 |
| 3 |
|
- | 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 | Except for the blower motor speed, are all of the functions of the HVAC control module inoperative? | - | Go to Step 13 | Go to Step 6 |
| 6 | Inspect the cooling system for the following conditions:
Did you find and correct the condition? |
- | Go to Step 22 | Go to Step 7 |
| 7 |
|
- | Go to HVAC Compressor Clutch Does Not Disengage | Go to Step 8 |
| 8 |
|
0-255 Counts | 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 22 | Go to Heating Performance Diagnostic (Front System) or Heating Performance Diagnostic (Auxiliary System) |
| 10 | Test the door control circuit of the air temperature actuator for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 22 | 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 22 | Go to Step 12 |
| 12 |
IMPORTANT:
Ensure that the HVAC control module connector is connected during this step in order to avoid misdiagnosis.
|
0 V at cold 12 V at hot |
Go to Step 17 | Go to Step 19 |
| 13 | Test the ignition 1 voltage circuit of the HVAC control module for an open or for a high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 22 | Go to Step 14 |
| 14 | Test the battery positive voltage circuit of the HVAC control module for an open or for a high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 22 | Go to Step 15 |
| 15 | Test the blower motor control OFF circuit of the HVAC control module for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 22 | Go to Step 16 |
| 16 | Test the ground circuit of the HVAC control module for an open. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 22 | Go to Step 21 |
| 17 | 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 22 | Go to Step 18 | |
| 18 | Inspect the air temperature actuator, door and any attaching linkage for binding or a condition that prevents drive shaft rotation. Did you find and correct the condition? |
- | Go to Step 22 | Go to Step 20 |
| 19 | 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 22 | Go to Step 21 |
| 20 | Replace the air temperature actuator. Refer to Air Temperature Actuator Replacement - Right (Dual Zone) or Air Temperature Actuator Replacement - Left (Dual Zone) . Did you complete the replacement? |
- | Go to Step 22 | - |
| 21 | Replace the HVAC control module. Refer to Control Module References
in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement? |
- | Go to Step 22 | - |
| 22 | Operate the system in order to verify the repair. Did you correct the condition? |
- | System OK | Go to Step 2 |