For 1990-2009 cars only
Diagnostic Trouble Code (DTC) Displaying for Buick Park Avenue 1999
The heater and the A/C programmer set the diagnostic trouble codes (DTC) for the air conditioning system. One of the following methods may display the DTC:
| • | The Scan Tool Display DTC selection |
| • | The on-board method |
| 1. | Press and hold the OFF, AUTO and the RECIRC buttons for 1 second. |
| 2. | The DTCs will display for 2 seconds each, and then return to normal operation. |
