Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Electronic Automatic Temperature Control Module On-Demand Self Test
The EATC Module On-Demand Self Test will retrieve on-demand (hard fault) DTCs only, it will not retrieve continuous DTCs. Continuous DTCs can be cleared when exiting the EATC Module On-Demand Self Test. Make sure to retrieve continuous DTCs by carrying out the ELECTRONIC AUTOMATIC TEMPERATURE CONTROL MODULE - Retrieve Continuous DTCs procedure before clearing any continuous DTCs.
- The EATC Module On-Demand Self Test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A diagnostic tool must be used to retrieve these concerns.
- The EATC Module On-Demand Self Test will detect concerns in the system control functions and will display on-demand (hard fault) DTCs for concerns that are present during the self-test. The vehicle interior temperature should be between 4°C-38°C (40°F-100°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false DTCs may be displayed.
- The self-test can be initiated after cycling the ignition switch from OFF to ON. Normal operation of the climate control system stops when the self-test is activated.
- To enter the self-test, press the OFF and DEFROST buttons simultaneously and release, then press the AUTO button within 2 seconds. The display will show a flashing blower icon for 20 seconds, after which all vacuum fluorescent segments will be displayed if there are no on-demand DTCs present. If DTCs are present, the EATC module will display "00 00" and then on-demand DTCs. Record all DTCs displayed.
- If any DTCs appear during the self-test, carry out the diagnostic procedure. Refer to the Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code (DTC) Index and follow the ACTION for each DTC given.
- If a condition exists, but no DTCs appear during the self-test, GO to SYMPTOM CHART Condition: The EATC System Is Inoperative, Intermittent or Incorrect Operation.
- To exit the self-test and retain all DTCs, press any button except DEFROST. The EATC module will exit the self-test and retain all DTCs.
- To exit the self-test and clear all DTCs, press the DEFROST button. The EATC module will exit the self-test and all DTCs will be cleared.
- Always exit the self-test before powering the system down (system turned OFF). Once the self-test is exited, the ignition switch must remain ON for at least 30 seconds to allow the door actuators to automatically recalibrate.
- Continuous DTCs will be deleted after 80 ignition switch ON cycles after the intermittent fault occurs.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.