P0481

DTC P0481: A/C Condenser Fan Control Circuit Malfunction

Wiring Diagram










Circuit Description

A/C condenser fan motor is turned ON and OFF by its relay which ECM controls. A/C condenser fan motor is turned ON when ECM outputs A/C ON signal to A/C control module (amplifier) or when engine coolant temp. is 110 °C, 230 °F or more.

DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

NOTE:

Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temp.: -14 °C, 6.8 °F or higher
- Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up engine to normal operating temperature.
4) Run engine at idle and turn both A/C switch and heater blower switch ON (turn ON air conditioning) for 3 min. or more.
5) Check DTC and pending DTC.

DTC Troubleshooting

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. Check wire circuit.

Disconnect A/C condenser fan control relay (1) from fuse / relay box with ignition switch turned OFF.
Turn ON ignition switch, measure voltage between engine ground to "LT GRN" wire terminal.





2. A/C compressor control relay

Is voltage 10 - 14 V?
YES
Go to Step 4.
NO
Go to Step 3.

3. Check wire circuit.

Disconnect A/C compressor control relay (2) from fuse / relay box with ignition switch turned OFF.
Turn ON ignition switch, measure voltage between engine ground to "LT GRN" wire terminal at A/C condenser fan control connector.





1. A/C condenser fan relay

Is voltage 10 - 14 V?
YES
Faulty A/C compressor control relay.
NO
"LT GRN" wire shorted to ground circuit.

4. Check wire circuit.

Connect A/C condenser fan control relay to fuse / relay box with ignition switch turned OFF.
Disconnect connector from ECM.
Turn ON ignition switch, measure voltage between vehicle body ground and "G04-32" terminal wire.

Is voltage 10 - 14 V?
YES
Go to Step 8.
NO
Go to Step 5.

5. Check wire circuit.

Disconnect A/C compressor control relay from fuse / relay box.
Measure resistance between "G04-32" terminal wire and vehicle body ground.

Is resistance infinity?
YES
Go to Step 6.
NO
"BLU/YEL" wire shorted to ground circuit.

6. Check wire circuit.

Turn ON ignition switch.
Check voltage between "G04-32" terminal wire and vehicle body ground.

Is voltage 0 V?
YES
Go to Step 7.
NO
"BLU/YEL" wire shorted to power supply circuit.

7. Check A/C condenser fan control relay.

Check A/C condenser fan control relay, referring to A/C Condenser Fan Control System Inspection A/C Condenser Fan Control System Inspection.

Is result in good condition?
YES
"BLU/YEL" wire open circuit.
NO
Replace relay.

8. Check A/C condenser fan control.

Connect connectors to ECM with ignition switch turned OFF.
Run engine and turn ON A/C switch.
Measure voltage between vehicle body ground and "G04-32" terminal wire.

Is voltage lower 1.5 V?
YES
Intermittent trouble.
Check for intermittent refer to Intermittent and Poor Connection Inspection.
If OK, substitute a known-good ECM and recheck.
NO
Faulty ECM.