DTC P0481 [13B-MSP]
id0102g1821100
DTC P0481 |
Cooling fan relay No.2 and No.3 control circuit problem |
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DETECTION CONDITION
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• 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.
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POSSIBLE CAUSE
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• 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
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Diagnostic procedure
STEP |
INSPECTION |
ACTION |
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1
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VERIFY RELATED SERVICE INFORMATION AVAILBAILITY
• Verify related Service information availability.
• Is any related Service information available?
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Yes
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Perform repair or diagnosis according to th available Service information.
• If the vehicle is not repaired, go to the next step.
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No
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Go to the next step.
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2
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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?
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Yes
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Repair or replace the terminal, then go to Step 9.
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No
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Go to the next step.
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3
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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:
• Is the voltage B+?
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Yes
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Go to the next step.
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No
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Repair or replace the wiring harness for a possible open circuit or short to ground, then go to Step 9.
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4
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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:
• Is there continuity?
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Yes
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Repair or replace the wiring harness for a possible short to ground, then go to Step 9.
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No
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Go to the next step.
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5
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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:
• Is the voltage B+?
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Yes
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Repair or replace the wiring harness for a possible short to power supply, then go to Step 9.
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No
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Go to the next step.
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6
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INSPECT COOLING FAN RELAY NO.2/NO.3
• Inspect the cooling fan relay No.2/No.3.
(See RELAY INSPECTION.)
• Is there any malfunction?
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Yes
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Replace the cooling fan relay No.2/No.3, then go to Step 9.
(See RELAY LOCATION.)
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No
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Go to the next step.
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7
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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?
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Yes
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Repair or replace the terminal, then go to Step 9.
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No
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Go to the next step.
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8
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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:
• Is there continuity?
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Yes
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Go to the next step.
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No
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Repair or replace the wiring harness for a possible open circuit, then go to the next step.
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9
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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?
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Yes
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Replace the PCM, then go to the next step.
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No
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Go to the next step.
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10
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VERIFY AFTER REPAIR PROCEDURE
• Perform the “AFTER REPAIR PROCEDURE”.
• Are any DTCs present?
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Yes
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Go to the applicable DTC inspection.
(See DTC TABLE [13B-MSP].)
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No
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DTC troubleshooting completed.
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