Reading and Clearing Diagnostic Trouble Codes

ELECTRONIC AUTOMATIC TEMPERATURE CONTROL MODULE SELF-TEST

- The EATC module self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A scan tool must be used to retrieve these concerns.
- The EATC module self-test will detect concerns in the system control functions and will display hard diagnostic trouble codes (DTCs). Hard DTC's identify faults which are present during the self-test. The vehicle interior/ambient temperature should be between 4-32°C (40-90°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false temperature sensor DTCs will be displayed.
- The self-test can be initiated at any time. Normal operation of the system stops when the self-test is activated.
- To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTO button within 2 seconds. The display will show the fan speed indicator illuminating from low to high. The test may run as long as 30 seconds. Record all DTCs displayed.
- If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.
- If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Incorrect Operation. Symptom Related Diagnostic Procedures
- To exit the self-test and clear all DTCs, press the FRONT DEFROST button. The EATC control assembly will then turn OFF (display blank) and all DTCs will be cleared.
- Always exit the self-test before powering the system down (system turned OFF).