DTC P0481

id010200815200

DTC P0481

Cooling fan relay No.2 control circuit malfunction

DETECTION CONDITION

• The PCM monitors the cooling fan relay No.2 control signal at PCM terminal 4L. If the PCM detects that the cooling fan relay No.2 control signal does not change coolant the temperature 108 °C {228 °F} or more, the PCM determines that the cooling fan relay No.2 control has malfunction.
Diagnostic support note
• This is a continuous monitor (other).
• The MIL does not illuminate.
• The FREEZE FRAME DATA is available if the PCM detects the above malfunction condition during the first drive cycle.
• The PENDING is available.
• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Cooling fan relay No.2 malfunction
• Connector or terminal malfunction
• Open circuit in wiring between the ENGINE fuse and cooling fan relay No.2 terminal E
• Open circuit in wiring between cooling fan relay No.2 terminal A and PCM terminal 1I
• Short to ground in wiring between cooling fan relay No.2 terminal A and PCM terminal 1I
• Short to power circuit between cooling fan relay No.2 terminal A and PCM terminal 1I
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
PERFORM DTC CONFIRMATION PROCEDURE
• Perform the DTC CONFIRMATION PROCEDURE.
• Is the same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists. Go to the INTERMITTENT CONCERN TROUBLESHOOTING procedure.
2
INSPECT COOLING FAN RELAY NO.2 CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect the cooling fan relay No.2 connector.
• Inspect for poor connection (such as damaged, pulled-out pins, and corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal and/or connector, then go to Step 9.
No
Go to the next step.
3
INSPECT COOLING FAN RELAY NO.2 POWER FOR OPEN CIRCUIT
• 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
Replace or replace the wiring harness for an open circuit, then go to Step 9.
4
INSPECT COOLING FAN RELAY NO.2
• Inspect cooling fan relay No.2.
• Is cooling fan relay No.2 normal?
Yes
Go to the next step.
No
Replace cooling fan relay No.2, then go to Step 9.
5
INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR SHORT TO POWER
• Measure the voltage between cooling fan relay No.2 terminal D (wiring harness-side) and body ground.
• Is the voltage B+?
Yes
Repair or replace the wiring harness for short to power, then go to Step 9.
No
Go to the next step.
6
INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR SHORT TO GROUND
• Inspect continuity between cooling fan relay No.2 terminal D (wiring harness- side) and body ground.
• Is there continuity?
Yes
Repair or replace the wiring harness for an open circuit, then go to Step 9.
No
Go to the next step.
7
INSPECT PCM CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• 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.
8
INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR OPEN CIRCUIT
• Inspect for continuity between the cooling fan relay No.2 terminal D (wiring harness-side) and PCM terminal 1I (wiring harness-side).
• Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for an open circuit, then go to the next step.
9
VERIFY TROUBLESHOOTING OF DTC P0481 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the WDS or equivalent.
• 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 applicable DTC troubleshooting.
(See DTC TABLE.)
No
Troubleshooting completed.