DTC P0481 [13B-MSP]

id0102g1821100

DTC P0481

Cooling fan relay No.2 and No.3 control circuit problem
DETECTION CONDITION
•  The PCM monitors the cooling fan relay No.2/No.3 control voltage when the PCM turns the cooling fan relay No.2/No.3 off. If the control voltage is low, the PCM determines that the cooling fan No.2/No.3 control circuit voltage is low.
•  The PCM monitors the cooling fan relay No.2/No.3 control voltage when the PCM turns the cooling fan relay No.2/No.3 on. If the control voltage is high, the PCM determines that the cooling fan No.2/No.3 control circuit voltage is high.
Diagnostic support note
•  This is a continuous monitor (other).
•  The MIL does not illuminate.
•  PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA is not available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Connector or terminal malfunction
•  Open circuit in wiring harness between main relay terminal C and cooling fan relay No.2 terminal A
•  Open circuit in wiring harness between main relay terminal C and cooling fan relay No.3 terminal A
•  Short to ground in wiring harness between main relay terminal C and cooling fan relay No.2 terminal A
•  Short to ground in wiring harness between main relay terminal C and cooling fan relay No.3 terminal A
•  Short to ground in wiring harness between cooling fan relay No.2 terminal E and PCM terminal 1N
•  Short to ground in wiring harness between cooling fan relay No.3 terminal E and PCM terminal 1N
•  Short to power supply in wiring harness between cooling fan relay No.2 terminal E and PCM terminal 1N
•  Short to power supply in wiring harness between cooling fan relay No.3 terminal E and PCM terminal 1N
•  Cooling fan relay No.2/No.3 malfunction
•  Open circuit in wiring harness between cooling fan relay No.2 terminal E and PCM terminal 1N
•  Open circuit in wiring harness between cooling fan relay No.3 terminal E and PCM terminal 1N
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY RELATED SERVICE INFORMATION AVAILBAILITY
•  Verify related Service information availability.
•  Is any related Service information available?
Yes
Perform repair or diagnosis according to th available Service information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
2
INSPECT COOLING FAN RELAY NO.2/NO.3 CONNECTOR FOR POOR CONNECTION
•  Turn the ignition switch off.
•  Disconnect the cooling fan relay No.2/No.3 connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
3
INSPECT COOLING FAN RELAY NO.2/NO.3 POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between the following circuits:
―  Cooling fan relay No.2 terminal A (wiring harness-side) and body ground
―  Cooling fan relay No.3 terminal A (wiring harness-side) and body ground
•  Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit or short to ground, then go to Step 9.
4
INSPECT COOLING FAN RELAY NO.2/NO.3 CONTROL CIRCUIT FOR SHORT TO GROUND
•  Turn the ignition switch off.
•  Inspect for continuity between the following circuits:
―  Cooling fan relay No.2 terminal E (wiring harness-side) and body ground
―  Cooling fan relay No.3 terminal E (wiring harness-side) and body ground
•  Is there continuity?
Yes
Repair or replace the wiring harness for a possible short to ground, then go to Step 9.
No
Go to the next step.
5
INSPECT COOLING FAN RELAY NO.2/NO.3 CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between the following circuits:
―  Cooling fan relay No.2 terminal E (wiring harness-side) and body ground
―  Cooling fan relay No.3 terminal E (wiring harness-side) and body ground
•  Is the voltage B+?
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.
6
INSPECT COOLING FAN RELAY NO.2/NO.3
•  Inspect the cooling fan relay No.2/No.3.
•  Is there any malfunction?
Yes
Replace the cooling fan relay No.2/No.3, then go to Step 9.
(See RELAY LOCATION.)
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, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
8
INSPECT COOLING FAN RELAY NO.2/NO.3 CONTROL CIRCUIT FOR OPEN CIRCUIT
•  Turn the ignition switch off.
•  Inspect for continuity between the following circuits:
―  Cooling fan relay No.2 terminal E (wiring harness-side) and PCM terminal 1N (wiring harness-side)
―  Cooling fan relay No.3 terminal E (wiring harness-side) and PCM terminal 1N (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 TROUBLESHOOTING OF DTC P0481 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine.
•  Is the PENDING CODE same as DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [13B-MSP].)
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.
(See DTC TABLE [13B-MSP].)
No
DTC troubleshooting completed.