For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 |

1. Engine idling.
2. Check for vacuum on the main vacuum supply source at the HVAC Programmer Vacuum Line Connector.

Is vacuum present?

Go to Step 2

Go to Step 5

2 | Using a vacuum pump, apply vacuum to each actuator line at the HVAC Programmer Vacuum Line Connector. Do all the lines hold vacuum? | Go to Step 3 | Go to Step 4
3 | Inspect the actuator doors for binding. Did you find and correct the condition? | Go to Step 7 | Go to Step 6
4 | Inspect each vacuum line for an open or restriction, if no open or restriction was found replace the appropriate actuator. | Go to Step 7 | --
5 | Locate condition and restore vacuum to source line. | Go to Step 7 | --
6 | Replace the HVAC Programmer. | Go to Step 7 | --
7 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | --