M/T
DTC P0480 - COOLING FAN RELAY 1 CIRCUIT LOW INPUTDTC DETECTING CONDITION:
- Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
- Radiator fan does not operate properly.
- Overheating
CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How To Clear Diagnostic Trouble Codes.
Wiring Diagram:
WIRING DIAGRAM
10AR1: CHECK OUTPUT SIGNAL FROM ECM.
1. Turn ignition switch to OFF.
2. Connect test mode connector at the lower portion of instrument panel (on the driver's side), to the side of the center console box.
3. Turn ignition switch to ON.
Connector & Terminal - [(B134) No.3 (+) - Chassis Ground (-)]:
4. While checking radiator fan relay operation,measure voltage between ECM terminal and ground.
NOTE: Radiator fan relay operation check can be executed using Subaru Select Monitor. For procedure, refer to "COMPULSORY VALVE OPERATION CHECK MODE".
CHECK: Does voltage change between 0 and 10 V?
YES: Repair poor contact in ECM connector.
NO: Go to step 10AR2.
10AR2: CHECK GROUND SHORT CIRCUIT IN RADIATOR FAN RELAY CONTROL CIRCUIT.
1. Turn ignition switch to OFF.
2. Disconnect connectors from ECM.
Connector & Terminal - [(B134) No.3 - Chassis Ground]:
3. Measure resistance of harness between ECM connector and chassis ground.
CHECK: Is the resistance less than 10 Ohms?
YES: Repair ground short circuit in radiator fan relay control circuit.
NO: Go to step 10AR3.
10AR3: CHECK POWER SUPPLY FOR RELAY.
1. Remove main fan relay from A/C relay holder.
2. Turn ignition switch to ON.
Connector & Terminal - [(F66) No.5 (+) - Chassis Ground (-)]:
3. Measure voltage between fuse and relay box (F/B) connector and chassis ground.
CHECK: Is the voltage more than 10 V?
YES: Go to step 10AR4.
NO: Repair open circuit in harness between ignition switch and fuse and relay box (F/B) connector.
10AR4: CHECK MAIN FAN RELAY.
1. Turn ignition switch to OFF.
Terminals - [No.5 - No.6]:
2. Measure resistance between main fan relay terminals.
CHECK: Is the resistance between 87 and 107 Ohms?
YES: Go to step 10AR5.
NO: Replace main fan relay.
10AR5: CHECK OPEN CIRCUIT IN MAIN FAN RELAY CONTROL CIRCUIT.
Connector & Terminal - [(B134) No.3 - (F66) No.6]:
Measure resistance of harness between ECM and main fan relay connector.
CHECK: Is the resistance less than 1 Ohm?
YES: Go to step 10AR6.
NO: Repair harness and connector.
NOTE: In this case, repair the following:
- Open circuit in harness between ECM and main fan relay connector
- Poor contact in coupling connector (F45)
10AR6: CHECK POOR CONTACT.
Check poor contact in ECM or main fan relay connector.
CHECK: Is there poor contact in ECM or main fan relay connector?
YES: Repair poor contact in ECM or main fan relay connector.
NO: Contact with Subaru of America (SOA) service.