DTC P0481 [L8, LF]

id0102b1815200

DTC P0481 | Cooling fan relay No.2 control circuit malfunction
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DETECTION CONDITION | • The PCM monitors the cooling fan relay No.2 control signal voltage and current. If the following conditions are met, the PCM determines that there is the cooling fan relay No.2 control circuit problem. ― The PCM turns the cooling fan relay No.2 off, but the voltage of the cooling fan relay No.2 control signal remains low. ― The PCM turns the cooling fan relay No.2 on, but the current of the cooling fan relay No.2 control signal remains 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. • FREEZE FRAME DATA (Mode 2/Mode 12) is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE | • Open circuit or short to ground in wiring harness between battery positive terminal and cooling fan relay No.2 terminal E ― Short to ground in wiring harness between battery positive terminal and cooling fan relay No.2 terminal E ― FAN 7.5 A fuse malfunction ― Open circuit in wiring harness between battery positive terminal and cooling fan relay No.2 terminal E • Cooling fan relay No.2 malfunction • PCM connector or terminals malfunction • Short to ground in wiring harness between cooling fan relay No.2 terminal A and PCM terminal 1N • Short to power supply between cooling fan relay No.2 terminal A and PCM terminal 1N • Open circuit in wiring harness between cooling fan relay No.2 terminal A and PCM terminal 1N • PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA (MODE 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (other related) been recorded? | Yes | Go to the next step.
No | Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on 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 CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND • Turn the ignition switch off. • 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 E (wiring harness-side) and body ground. • Is the voltage B+? | Yes | Go to the next step.
No | Inspect the FAN 7.5 A fuse. If the fuse is melt: • Repair or replace the wiring harness for a possible short to ground, then 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. (See RELAY INSPECTION.) • 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 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 the connector or terminals, then go to Step 9.
No | Go to the next step.
6 | INSPECT COOLING FAN RELAY NO.2 CONTROL CIRCUIT FOR SHORT TO GROUND • Cooling fan relay No.2 is removed and PCM connector is disconnected. • Inspect for continuity between cooling fan relay No.2 terminal A (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.
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 A (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 • Cooling fan relay No.2 is removed and PCM connector is disconnected. • Turn the ignition switch off. • Inspect for continuity between cooling fan relay No.2 terminal A (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 DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using M-MDS. (See AFTER REPAIR PROCEDURE [L8, LF].) • Perform the KOEO/KOER self test. (See KOEO/KOER SELF TEST [L8, LF].) • Is the same DTC present? | Yes | Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [L8, LF].)
No | Go to the next step.
10 | VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [L8, LF].) • Are any DTCs present? | Yes | Go to the applicable DTC troubleshooting. (See DTC TABLE [L8, LF].)
No | DTC troubleshooting completed.