Pre-Computer Aided Diagnostics
Symptom AIf the display symbols and indicators do not illuminate and no failure code is displayed, refer to "Computer Aided Diagnostic" for test procedures, then select a mode that will display the malfunction. If the ATC system operates properly but the display does not, refer to Symptom 3 under Non-Computer Aided Diagnostics.
Symptom B
The blower motor does not operate and no failure code is displayed. Stand clear of the blower motor and PVM heat sink. Do not run system for more than 10 minutes with the PVM removed from the A/C unit.
1. Check all PVM and blower motor electrical connections.
2. Using a suitable voltmeter, check for battery voltage at both ends of fuse 4. If fuse is good, disconnect blower motor lead from wire harness connector, then check 12 volts at green wire. If 12 volts is not detecting, repair feed circuit.
3. If 12 volts is supplied at green wire, connect negative lead of voltmeter to black wire of harness connector, then raise and lower the blower motor speed selector and note voltmeter indications. Voltmeter should read 3 volts low and 12 volts high. If voltage does not read as specified, replace the PVM, then retest system.
4. If all voltages are normal, repair or replace blower motor.
Symptom C
Air is not being directed from panel outlets with engine running and no failure code is displayed.
1. Disconnect vacuum harness from PVM connector.
2. Using a suitable vacuum gauge, check black line orifice of vacuum harness for engine manifold vacuum. Ensure vacuum is maintained for approximately 2 minutes after engine has been turned off to ensure proper operation of check valve. If necessary, repair vacuum supply circuit or replace vacuum check valve which is located over the A/C housing, behind the instrument panel.
3. If the vacuum supply and check valves are satisfactory, replace the PVM and test system.
Symptom D
The outlet air temperature does not become hot then cycle to cold during self-test operation. Refer to Symptom 4 under Non-Computer Aided Diagnostics.