DTC P0481:00 [ZJ, ZY]


id0102c0704700

DTC P0481:00

Cooling fan relay No.2 control circuit problem

DETECTION CONDITION
•  If the voltage remain low or high, the PCM determines that the cooling fan relay No.2 control has a malfunction.
Diagnostic support note
•  This is continuous monitor (other).
•  The MIL does not illuminate.
•  FREEZE FRAME DATA is available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Open circuit or short to ground in cooling fan relay No.2 power supply circuit
―  Short to ground in wiring harness between ignition switch and cooling fan relay No.2 terminal B
―  METER 10 A fuse malfunction
―  Open circuit in wiring harness between ignition switch and cooling fan relay No.2 terminal B
•  Cooling fan relay No.2 malfunction
•  Short to ground in wiring harness between cooling fan relay No.2 terminal D and PCM terminal 1AZ
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between cooling fan relay No.2 terminal D and PCM terminal 1AZ
•  Open circuit in wiring harness between cooling fan relay No.2 terminal D and PCM terminal 1AZ
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED
•  Have the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (other related) been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT COOLING FAN RELAY NO.2 POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND
•  Remove the cooling fan relay No.2.
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between cooling fan relay No.2 terminal B (wiring harness-side) and body ground.
•  Is the voltage B+?
Yes
Go to the next step.
No
Inspect the METER 10 A fuse.
•  If the fuse is melt:
―  Repair or replace the wiring harness for a possible short to ground.
―  Replace the fuse.
•  If the fuse is deterioration:
―  Replace the fuse.
•  If the fuse is normal:
―  Repair or replace the wiring harness for a possible open circuit.
Go to Step 9.
4
INSPECT COOLING FAN RELAY NO.2
•  Turn the ignition switch off.
•  Inspect the cooling fan relay No.2.
•  Is there any malfunction?
Yes
Replace the cooling fan relay No.2, then go to Step 9.
No
Go to the next step.
5
INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR SHORT TO GROUND
•  Cooling fan relay No.2 is removed.
•  Inspect for continuity between cooling fan relay No.2 terminal D (wiring harness-side) and body ground.
•  Is there continuity?
Yes
If the short to ground circuit could be detected:
•  Repair or replace the wiring harness for a possible short to ground.
If the short to ground circuit could not be detected:
•  Replace the PCM (short to ground in PCM internal circuit).
Go to Step 9.
No
Go to the next step.
6
INSPECT PCM CONNECTOR AND TERMINALS
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged, pulled-out pins, and corrosion).
•  Is there any malfunction?
Yes
Repair or replace terminal and/or connector, then go to Step 9.
No
Go to the next step.
7
INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Cooling fan relay No.2 is removed and PCM connector is disconnected.
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between cooling fan relay No.2 terminal D (wiring harness-side) and body ground.
•  Is there any voltage?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 9.
No
Go to the next step.
8
INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR OPEN CIRCUIT
•  Turn the ignition switch off.
•  Cooling fan relay No.2 is removed and PCM connector is disconnected.
•  Inspect for continuity between cooling fan relay No.2 terminal D (wiring harness-side) and PCM terminal 1AZ (wiring harness-side).
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using M-MDS.
•  Perform the KOEO/KOER self test.
•  Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.