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 concerns that can be readily identified, repair as necessary.
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.
- check that the battery voltage is greater than 9V.
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- or UBP circuits fault = ALL MODULE NO RESPONSE/NOT EQUIPPED, go to Module Communication Network Diagnostics 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 Electronic Automatic Temperature Control (DATC) Module Diagnostic Trouble Code (DTC) Index
8. If no DTCs related to the concern are retrieved, GO to Symptom Chart to continue the diagnostics. Symptom Related Diagnostic Procedures
9. If the DATC module cannot be accessed by the diagnostic tool, GO to Pinpoint Test A. Test A: No Communication With the Dual Automatic Temperature Control (DATC) Module
Dual Electronic Automatic Temperature Control (DATC) Module Diagnostic Trouble Codes - DTCs
If using the diagnostic tool or front panel diagnostics to check for DATC DTCs:
1. Check continuous DTCs.
2. Run DATC self-test. Refer to Front Panel DATC Self-Test (On-Demand Diagnostic Trouble Codes - DTCs).
General Information:
- If the DTC is continuous only and does not appear in the self-test, this indicates an intermittent fault condition, such as a poor wiring connection or a loose terminal. If the DATC does not appear after running the self-test it may also indicate that the DTC may no longer exist.
- If the DTC is continuous and appears in the self-test, this indicates a hard fault. A hard fault suggests a permanent wiring failure, disconnected connector or component failure.
Front Panel DATC Module Self-Test (On-Demand Diagnostic Trouble Codes - DTCs)
On-demand DTCs are those that are reported by an ECU when a failure is detected while executing a diagnostic test. For the DATC module this means that all faults (hard) that occur while the module is conducting a self-test shall be reported as an on-demand DTC.
- The DATC module self-test will not detect concerns associated with data link messages such as engine coolant temperature or vehicle speed signals. The diagnostic tool must be used to retrieve these concerns.
- The vehicle interior temperature should be between 0-32°C (32-90°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false temperature sensor DTCs may be displayed.
The DATC module self-test through the front panel display:
- can be initiated at any time. Normal operation of the system stops when the self-test is activated.
- is entered by pressing the OFF and DEFROST buttons simultaneously and then pressing the AUTO button within 2 seconds. Record all DTCs displayed.
- concludes by reporting all on-demand DTCs. Follow the diagnostics procedure given under ACTION in the DTC index for each DTC given.
- reports individual on-demand DTCs as 4-digit DTCs (less the alpha character).
- will calibrate all the mode doors and check all analog inputs. The DATC module will only report on-demand (hard) faults that occurred while the DATC module was conducting its self-test.
- will light all control panel display segments if no faults are detected.
- will report individual on-demand DTCs without the °C symbol lit.
To exit the self-test, press the DEFROST button. This will clear all on-demand codes from the DATC module memory. If no button is pushed, DTCs will continue to be displayed.
Upon exit from the self-test the DATC module returns to operational status. The DATC module executes a hard (cold boot) reset which places the DATC system in the OFF mode.
If a condition exists but no DTCs appear during the self-test, GO to Symptom Chart Condition: The DATC System Is Inoperative, Intermittent or Incorrect Operation. Symptom Related Diagnostic Procedures
Always exit the self-test before powering the system down (system turned OFF).
Front Panel DATC Module Display - Retrieve Continuous Diagnostic Trouble Codes (DTCs)
Continuous DTCs are fault codes recorded by the DATC module which have occurred during normal operation. For the DATC module this means that all faults (intermittent or hard) that occur while the module is in an operational state shall be reported as a continuous DTC.
- To retrieve continuous DTCs, press the OFF and DEFROST buttons simultaneously, followed by pressing the RECIRC button within 2 seconds.
- The DATC module will report all continuous DTCs to the vacuum fluorescent (VF) display.
- The DATC module will not carry out a self-test; it will only display continuous faults codes which are stored in memory.
- All VF display segments will light if no faults are detected.
- Individual continuous DTCs will be reported with the °C symbol lit.
- DTCs shall be reported as a 4-digit DTC (less the alpha character).
- Pressing the front DEFROST button will exit the retrieve continuous DTCs mode and clear all continuous DTCs from DATC module memory.
- Pressing any other button (other than DEFROST) will exit the retrieve continuous DTCs mode and maintain all continuous DTCs in DATC module memory.
- Upon exit from the retrieve continuous DTCs mode the DATC module returns to operational status. The DATC module executes a hard (cold boot) reset which places the DATC system in the OFF mode.