Initial Inspection and Diagnostic Overview
INSPECTION AND VERIFICATION1. Verify the customer's concern by operating the climate control system to duplicate the condition.
Visual Inspection Chart:
2. Inspect to determine if one of the mechanical or electrical concerns apply:
3. As pinpoint tests and measurements are being carried out, be sure to inspect for any disconnected, loose-fitting or incorrectly installed component, module and in-line electrical connectors and pins.
4. If the inspection reveals obvious concern(s) that can be readily identified, repair as required.
5. If the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the diagnostic tool menu. If the vehicle selection cannot be entered:
- check that the program card is correctly installed.
- check the connections to the vehicle.
- check the ignition switch position.
If the diagnostic tool still does not allow the vehicle selection to be entered, refer to the diagnostic tool manual.
6. Carry out the DATA LINK DIAGNOSTIC TEST using the diagnostic tool. If the diagnostic tool responds with:
- SCP+, SCP-, CAN or UBP circuits fault = ALL MODULE NO RESPONSE/NOT EQUIPPED, go to Communication System Diagnostics in Information Bus (Module Communications Network) to diagnose the network concern.
- If the powertrain control module (PCM) is not listed for a communication concern, turn the A/C controls to OFF and execute the self-test diagnostics for the PCM.
- If the EATC module is not listed for a communication concern, execute the self-test diagnostics for the EATC module.
7. If any PCM or EATC DTCs are retrieved, and are related to the concern, go to the Powertrain Control Module Diagnostic Trouble Code (DTC) Index or the Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code (DTC) Index to continue the diagnostics. Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code DTC) Index
8. If no DTCs related to the concern are retrieved, go to the Symptom Chart to continue the diagnostics. Symptom Related Diagnostic Procedures
9. If the Electronic Automatic Temperature Control module cannot be accessed by the diagnostic tool, GO to Pinpoint Test H. Test H: No Communication With The Electronic Automatic Temperature Control Module
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 diagnostic 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 a pulse tracer going around the center of the display window. 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).
Electronic Automatic Temperature Control Module - Display Continuous Codes
- This function will display continuous (intermittent) codes and hard faults that occur during normal operation.
- The display of continuous codes can be initiated at any time. Normal operation of the system stops when the display of continuous codes is activated. Note that "°C" will be displayed while in this mode.
- To display continuous codes, press the OFF and FLOOR buttons simultaneously and then release and within 2 seconds press the RECIRC button.
- To exit the display of continuous codes, press the FRONT DEFROST button. This will exit and clear all DTCs. Press the FLOOR button to exit without clearing DTCs set before the last ignition cycle.
- Always exit continuous codes display before powering the system down (system turned off).
- Continuous DTCs are saved only after an ignition cycle.
- Continuous DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.