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 scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan 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 scan tool still does not allow the vehicle selection to be entered, refer to the scan tool manual.
6. Carry out the DATA LINK DIAGNOSTIC TEST using the scan tool. If the scan tool responds with:
- SCP+, SCP- 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 DATC module is not listed for a communication concern, execute the self-test diagnostics for the DATC module.
7. If any PCM or DATC DTCs are retrieved, and are related to the concern, go to the Powertrain Control Module Diagnostic Trouble Code (DTC) Index or the Dual Automatic Temperature Control (DATC) Module Diagnostic Trouble Code (DTC) Index to continue the diagnostics. Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index Dual Automatic Temperature Control (DATC) 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 Dual Automatic Temperature Control module cannot be accessed by the scan tool, GO to Pinpoint Test H. Test H: No Communication With The Dual Automatic Temperature Control Module
Dual Automatic Temperature Control Module Self-Test
- The DATC 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 DATC 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 RECIRC button within two 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 DATC System Is Inoperative, Intermittent or Incorrect Operation.
- To exit the self-test and clear all DTCs, press the FRONT DEFROST button. The DATC 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).
Dual 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 PANEL buttons simultaneously and then release and within two seconds press the AUTO 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.