How to Enter Diagnostics Using Control Head

Retrieving Fault Codes
1. To begin the Fault Code Tests you must be in the Select Test mode. With a "00" value displayed in the Test Selector and no stick man, push either the A/C or Recirc button.
2. The stick man will appear indicating you have entered the Fault Code Tests. The values displayed in the Test Selector will range from "00" to "64."
3. Fault codes will appear and repeat if there are more than one. Record all of the fault codes, then see the Current and Historical Fault Code charts for the descriptions. If there are no fault codes, the "00" display value will remain displayed in the Test Selector.
4. If a Fault Code "25" or "29" is displayed, the ATC control module must be replaced before any further testing is performed.
5. For more detailed information about a fault code, see the Input Circuit Tests or the Output Circuit/Actuator Tests.