- The dual temperature control is inoperative/does not operate correctly
- DATC module configuration.
- DATC module.
- Coolant control valve.
- Low coolant level.
- Air trapped in coolant circuit.
- Incorrect heater hose connections.
- Air temperature sensors.
Visual Inspection Chart
- Loose, missing or damaged A/C compressor drive belt
- Loose or disconnected A/C clutch
- Broken or leaking refrigerant lines
- Obstructed in-vehicle temperature sensor
- Disconnected in-vehicle temperature aspirator hose
- A/C registers are not working (open/close)
- Front floor ducts not in place
- Incorrectly installed in-vehicle temperature sensor
- Incorrectly installed ambient air temperature sensor
- Blower motor inoperative
- A/C compressor inoperative
- Circuit short/open.
- Disconnected, loose fitting, or incorrectly installed electrical connectors and pins
- Cooling fan inoperative
- Relays not functional or not installed
- As pinpoint tests and measurements are being performed, be sure to inspect for any disconnected, loose fitting, or incorrectly installed component, module and in-line electrical connectors and pins.
- If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
- 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.
- check that the battery voltage is greater than 9V.
you can do this test
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 FLOOR buttons simultaneously and then pressing the AUTO button within two seconds. The display will show counts of 1 to 25 in the center of the display window. 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 four-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 any 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.
Always exit the self-test before powering the system down (system turned OFF).