DTC P0481:00 [LF, L5]

id0102c8704700

DTC P0481:00

Cooling fan relay No.2 and No.3 control circuit malfunction
DETECTION CONDITION
•  The PCM monitors the cooling fan relay No.2 and No.3 control signal voltage and current. If the following conditions are met, the PCM determines that there is the cooling fan relay No.2 and No.3 control circuit problem.
―  The PCM turns the cooling fan relay No.2 and No.3 off, but the voltage of the cooling fan relay No.2 and No.3 control signal remains low.
―  The PCM turns the cooling fan relay No.2 and No.3 on, but the current of the cooling fan relay No.2 and No.3 control signal remains high.
Diagnostic support note
•  This is a continuous monitor (Other).
•  The MIL does not illuminate.
•  FREEZE FRAME DATA is not available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Cooling fan relay No.2 or No.3 malfunction
•  Connector or terminal malfunction
•  Open circuit in wiring harness between ignition switch*1, ignition relay*2 and cooling fan relay No.3 terminal A
•  Open circuit in wiring harness between ignition switch*1, ignition relay*2 and cooling fan relay No.2 terminal E
•  Open circuit in wiring harness between cooling fan relay No.3 terminal E and PCM terminal 1R
•  Open circuit in wiring harness between cooling fan relay No.2 terminal A and PCM terminal 1R
•  Short to ground in wiring harness between cooling fan relay No.3 terminal E and PCM terminal 1R
•  Short to ground in wiring harness between cooling fan relay No.2 terminal A and PCM terminal 1R
•  Short to power supply in wiring between cooling fan relay No.3 terminal E and PCM terminal 1R
•  Short to power supply in wiring harness between cooling fan relay No.2 terminal A and PCM terminal 1R
•  PCM malfunction

*1  :Without Advanced keyless entry and push button start system
*2  :With Advanced keyless entry and push button start system
*3  :Vehicles with three cooling fan relay
*4  :Vehicles with four cooling fan relay

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Check for 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 POOR CONNECTION OF COOLING FAN RELAY NO.2 OR NO.3 CONNECTOR
•  Switch the ignition to off.
•  Disconnect the cooling fan relay No.2 and No.3 connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal and/or connector, then go to Step 10.
No
Go to the next step.
4
INSPECT COOLING FAN RELAY NO.2 OR NO.3 POWER CIRCUIT FOR OPEN CIRCUIT
•  Switch the ignition to ON (Engine off).
•  Measure voltage between following terminals and body ground.
•  Cooling fan relay No.2 terminal E (wiring harness-side)
•  Cooling fan relay No.3 terminal A (wiring harness-side)
•  Is voltage B+?
Yes
Go to the next step.
No
Replace or replace the wiring harness for an open circuit, then go to Step 10.
5
INSPECT COOLING FAN RELAY NO.2 OR NO.3
•  Inspect cooling fan relay No.2 or No.3.
•  Is cooling fan relay No.2 or No.3 normal?
Yes
Go to the next step.
No
Replace the cooling fan relay No.2 or No.3, then go to Step 10.
6
INSPECT COOLING FAN RELAY NO.2 OR NO.3 CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Measure voltage between following terminals and body ground.
•  Cooling fan relay No.2 terminal A (wiring harness-side)
•  Cooling fan relay No.3 terminal E (wiring harness-side)
•  Is voltage B+?
Yes
Repair or replace the wiring harness for short to power supply, then go to Step 10.
No
Go to the next step.
7
INSPECT COOLING FAN RELAY NO.2 OR NO.3 CONTROL CIRCUIT FOR SHORT TO GROUND
•  inspect for continuity between following terminals and body ground.
•  Cooling fan relay No.2 terminal A (wiring harness-side)
•  Cooling fan relay No.3 terminal E (wiring harness-side)
•  Is there continuity?
Yes
Repair or replace the wiring harness for an open circuit, then go to Step 10.
No
Go to the next step.
8
INSPECT POOR CONNECTION OF PCM CONNECTOR
•  Switch the ignition to off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal and/or connector, then go to Step 10.
No
Go to the next step.
9
INSPECT COOLING FAN RELAY NO.2 OR NO.3 CONTROL CIRCUIT FOR OPEN CIRCUIT
•  inspect for continuity between following terminals and PCM terminal 1R (wiring harness-side).
•  Cooling fan relay No.2 terminal A (wiring harness-side)
•  Cooling fan relay No.3 terminal E (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.
10
VERIFY TROUBLESHOOTING OF DTC P0481:00 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M‐MDS.
•  Perform the KOEO or KOER self-test.
•  Is the DTC P0481:00 present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [L8, LF, L5].)
No
Go to the next step.
11
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “After Repair Procedure”.
•  Is any DTC present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [L8, LF, L5].)
No
Troubleshooting completed.

*1  :Without Advanced keyless entry and push button start system
*2  :With Advanced keyless entry and push button start system
*3  :Vehicles with three cooling fan relay
*4  :Vehicles with four cooling fan relay