P0481

DTC P0481

DTC Detecting Condition and Trouble Area






Wiring Diagram

Refer to P0480 DTC P0480.

DTC Confirmation Procedure

1) Start engine and warm up to normal operating temperature.
2) Keep engine at idle speed until engine coolant temperature reaches 104 °C (219.2 °F) or more.

DTC Troubleshooting

1.
Was "Engine and Emission Control System Check" performed?
YES -
Go to Step 2.
NO -
Go to Engine and Emission Control System Check Engine and Emission Control System Check.

2. Radiator cooling fan relay No.2 power supply circuit (coil side) check

Turn OFF ignition switch and remove radiator cooling fan relay No.2.
Check for proper terminal connection to cooling fan relay No.2 connector.
If connections are OK, check that voltage between radiator cooling fan relay No.2 power supply circuit (coil side) (A2) and vehicle body ground is battery voltage with ignition switch in ON position.

Is it in good condition?
YES -
Go to Step 3.
NO -
Repair or replace defective wire harness.

3. Radiator cooling fan relay check

Check radiator cooling fan relay No.2. Testing and Inspection

Is it in good condition?
YES -
Go to Step 4.
NO -
Replace radiator cooling fan relay No.2.

4. Radiator cooling fan relay No.2 drive circuit check

Turn OFF ignition switch and disconnect connectors from ECM.
Check that radiator cooling fan relay No.2 drive circuit (B2) is as follows.
- Wiring harness resistance of radiator cooling fan relay No.2 drive circuit is less than 3 ohms.
- Insulation resistance between radiator cooling fan relay No.2 drive circuit and vehicle body ground is infinity.
- Insulation resistance of wire harness is infinity between radiator cooling fan No.2 drive circuit terminal and each terminal at radiator cooling fan relay No.2 connector.
- Circuit voltage of radiator cooling fan relay No.2 drive circuit is 0 - 1 V with ignition switch in ON position.

Is it in good condition?
YES -
Substitute a known-good ECM and recheck.
NO -
Repair or replace defective wire harness.