Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 3: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
- 4: This step determines if the engine control module (ECM) has set any DTCs related to the HVAC system.
Diagnostic System Check - HVAC Systems - Manual
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Did you review the HVAC Preliminary Checks in Heating, Ventilation, and Air Conditioning? | Go to Step 2 | Go to HVAC Preliminary Checks in Heating, Ventilation and Air Conditioning |
| 2 | Install a scan tool. Does the scan tool power up? |
Go to Step 3 | Go to Scan Tool Does Not Power Up in Data Link Communications |
| 3 |
|
Go to Step 4 | Go to Scan Tool Does Not Communicate with Component in Data Link Communications |
| 4 | Select the display DTCs function on the scan tool for the ECM. Does the scan tool display DTC P0532, P0533, or P0645? |
Go to Diagnostic Trouble Code (DTC) List | Go to Step 5 |
| 5 | Does the scan tool display any other DTCs? | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 1.6L (L91) |
Go to Symptoms - HVAC Systems - Manual |