A: EATC SYSTEM INOPERATIVE, INTERMITTENT OR IMPROPER OPERATION

PINPOINT TEST A: EATC SYSTEM INOPERATIVE, INTERMITTENT OR IMPROPER OPERATION

A1 PERFORM EATC SELF TEST

- Turn EATC System ON. Press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The test may take as long as 30 seconds. A pulse tracer will circle around the center of the VFD window during the test. When the self test is completed, error codes will be displayed in the VFD window to list faults found during the self test. Error codes will also be given for intermittent faults encountered during system operation. Record these error codes.

- Were error codes other than 888 displayed in the VFD window?

- Yes
Refer to Inspection and Verification for Diagnostic Error Codes to find the "Detected Condition." Perform the necessary diagnosis and make repairs.

- No
Go to A2.

A2 CHECK BLOWER MANUAL OVERRIDE LOW SPEED OPERATION

- Rotate the blower thumbwheel down to the stop.

- Does the blower motor go to low speed?

- Yes
Go to A3.

- No
Refer to Pinpoint Test E.

A3 CHECK BLOWER MANUAL OVERRIDE HIGH SPEED OPERATION

- Rotate the blower thumbwheel up to the stop.

- Does the blower motor go to high speed?

- Yes
Go to A4.

- No
Refer to Pinpoint Test F.

A4 VERIFY DEFROST OVERRIDE OPERATION

- Press the Defrost button and check system discharge airflow. Airflow should be from the demister nozzle and duct and the A/C side window demister and hose. Also check to be sure the heater and A/C air inlet duct door is in the outside position.

- Are these two conditions met?

- Yes
Go to A5.

- No
Check system for vacuum leaks. Retest system.

A5 VERIFY FLOOR OVERRIDE OPERATION

- Press the FLOOR button and check system discharge airflow. Discharge airflow should be from the heater outlet floor duct.

- Is airflow discharged from the heater outlet floor duct?

- Yes
Go to A6.

- No
Check system for vacuum leaks. Retest system.

A6 VERIFY VENT OVERRIDE OPERATION

- Press the VENT button and check system discharge airflow. Airflow should be from the A/C registers.

- Is this condition met?

- Yes
Go to A7.

- No
Check system for vacuum leaks. Retest system.

A7 VERIFY MAX A/C OVERRIDE OPERATION

- With the ambient temperature above 5°C (40°F), press the MAX A/C button. Check that the heater and A/C air inlet duct door is in the recirc. air position (closed to outside air).

- Is the outside-recirc door closed to outside air?

- Yes
Go to A8.

- No
Check system for vacuum leaks. Retest system.

A8 VERIFY A/C CLUTCH DOES NOT ENGAGE IN VENT

- Press the VENT button. VENT should be displayed and the A/C clutch should not engage.

- Are these two conditions met?

- Yes
Go to A9.

- No
Go to Heating and Air Conditioning/Compressor HVAC. Compressor HVAC

A9 VERIFY MAX A/C OPERATION

- Press the MAX A/C button again. MAX A/C should be displayed and the A/C clutch should engage for A/C compressor operation.

- Are these two conditions met?

- Yes
Go to A10.

- No
Go to General System Diagnosis.
A10 VERIFY AUTOMATIC OPERATION

- Press the AUTOMATIC button. The selected temperature and AUTOMATIC should be shown in the VFD display window.

- Is the VFD correct and complete?

= Yes
GO to A11 if equipped with optional steering wheel remote control buttons. Test complete on vehicles without remote control buttons. Restore vehicle.

- No
Refer to EATC Self Test in Pinpoint Test Step A1 and Diagnostic Error Codes in Inspection and Verification.

A11 VERIFY STEERING WHEEL TEMP BUTTON OPERATION

- Operate the steering wheel remote control TEMP button to verify that the set temperature increases when the "/\" (increase) side of the button is pushed and decreases when the "\/" (lower) side of the button is depressed.

- Does the TEMP switch increase and decrease the set temperature as described?

- Yes
Go to A12.

- No
Refer to Instrument Panel, Gauges and Warning Indicators. Instrument Panel, Gauges and Warning Indicators

A12 VERIFY STEERING WHEEL FAN SWITCH OPERATION

- Operate the steering wheel remote control FAN button to verify that the blower speed increases when FAN "/\" (increase) is depressed and that the blower speed decreases when FAN "\/" (lower) is depressed.

- Does the FAN button increase and decrease the blower motor speed as described?

- Yes
Test complete. Restore vehicle.

- No
Refer to Instrument Panel, Gauges and Warning Indicators. Instrument Panel, Gauges and Warning Indicators