Symptom:
*REAR BOOSTER FAN REAR CONTROL SWITCH ON INDICATOR
INOPERATIVE - ATC
POSSIBLE CAUSES
REAR BOOSTER FAN REAR CONTROL SWITCH
REAR FAN ON INDICATOR DRIVER CIRCUIT SHORTED TO GROUND
REAR FAN ON INDICATOR DRIVER CIRCUIT OPEN
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST
ACTION
APPLICABILITY
1
Turn the ignition off.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Turn the ignition on.
Press the REAR fan mode switch on.
Measure the voltage of the Rear Fan On Indicator Driver circuit.
Is the voltage between 7 and 9 volts?
All
Yes
→ Replace the Rear Booster Fan Rear Control Switch in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Go To 2
2
Turn the ignition off.
Disconnect the ATC C2 harness connector.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Measure the resistance between ground and the Rear Fan On Indicator Driver
circuit.
Is the resistance below 10K ohms?
All
Yes
→ Repair the Rear Fan On Indicator Driver circuit for a short to
ground.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Go To 3
3
Turn the ignition off.
Disconnect the ATC C2 harness connector.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Measure the resistance of the Rear Fan On Indicator Driver circuit between the ATC
C2 harness connector and the Rear Booster Fan Rear Control Switch harness
connector.
Is the resistance below 5.0 ohms?
All
Yes
→ Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Repair the Rear Fan On Indicator Driver circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
661
HEATING & A/C