DTC P0481:00 [MZR 2.0 DISI]

id0102f5704700


Vehicles with three cooling fan relays

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 for 5 s.
―  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 for 5 s.
Diagnostic support note
•  This is a continuous monitor (other).
•  The MIL does not illuminate.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Cooling fan relay No.2 and/or No.3 malfunction
•  Short to ground or open circuit in cooling fan relay No.2 and/or No.3 power supply circuit
―  Short to ground in wiring harness between the following terminals:
•  ENGINE IG 15 A fuse—Cooling fan relay No.2 terminal E
•  ENGINE IG 15 A fuse—Cooling fan relay No.3 terminal A
―  ENGINE IG 15 A fuse malfunction
―  Open circuit in wiring harness between the following terminals:
•  Ignition switch*1/Relay block*2—Cooling fan relay No.2 terminal E
•  Ignition switch*1/Relay block*2—Cooling fan relay No.3 terminal A
•  Short to ground in wiring harness between the following terminals:
―  Cooling fan relay No.2 terminal A—Cooling fan relay No.3 terminal E
―  Cooling fan relay No.3 terminal E—PCM terminal 1V
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between the following terminals:
―  Cooling fan relay No.2 terminal A—Cooling fan relay No.3 terminal E
―  Cooling fan relay No.3 terminal E—PCM terminal 1V
•  Open circuit in wiring harness between the following terminals:
―  Cooling fan relay No.2 terminal A—Cooling fan relay No.3 terminal E
―  Cooling fan relay No.3 terminal E—PCM terminal 1V
•  PCM malfunction

*1  :Vehicles without advanced keyless entry and push button start system
*2  :Vehicles with advanced keyless entry and push button start system

Diagnostic procedure

STEP

INSPECTION

ACTION
1
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.
2
INSPECT COOLING FAN RELAY NO.2 AND NO.3
•  Switch the ignition to off.
•  Remove the cooling fan relay No.2 and No.3.
•  Inspect the cooling fan relay No.2 and No.3.
•  Is there any malfunction?
Yes
Replace the cooling fan relay No.2 and/or No.3, then go to Step 8.
No
Go to the next step.
3
INSPECT COOLING FAN RELAY NO.2 AND NO.3 POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT
•  Cooling fan relay No.2 and No.3 are removed.
•  Switch the ignition to ON (engine off).
•  Measure the voltage at the following terminals (wiring harness-side):
―  Cooling fan relay No.2 terminal E
―  Cooling fan relay No.3 terminal A
•  Is the voltage B+?
Yes
Go to the next step.
No
Inspect the ENGINE IG 15 A fuse.
•  If the fuse is melt:
―  Repair or replace the wiring harness for a possible short to ground.
―  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 8.
4
INSPECT COOLING FAN RELAY NO.2 AND NO.3 SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Cooling fan relay No.2 and No.3 are removed.
•  Switch the ignition to off.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
―  Cooling fan relay No.2 terminal A
―  Cooling fan relay No.3 terminal E
•  Is there continuity?
Yes
If the short to ground circuit could be detected:
•  Repair or replace the wiring harness for a possible short to ground.
If the short to ground circuit could not be detected:
•  Replace the PCM (short to ground in the PCM internal circuit).
Go to Step 8.
No
Go to the next step.
5
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 8.
No
Go to the next step.
6
INSPECT COOLING FAN RELAY NO.2 AND NO.3 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Cooling fan relay No.2 and No.3 are removed.
•  PCM connector is disconnected.
•  Switch the ignition to ON (engine off).
•  Measure the voltage at the following terminals (wiring harness-side):
―  Cooling fan relay No.2 terminal A
―  Cooling fan relay No.3 terminal E
•  Is there any voltage?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 8.
No
Go to the next step.
7
INSPECT COOLING FAN RELAY NO.2 AND NO.3 SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  Cooling fan relay No.2 and No.3 are removed.
•  PCM connector is disconnected.
•  Switch the ignition to off.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  Cooling fan relay No.2 terminal A—Cooling fan relay No.3 terminal E
―  Cooling fan relay No.3 terminal E—PCM terminal 1V
•  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.
8
VERIFY DTC TROUBLESHOOTING 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 same DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI].)
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 2.0 DISI].)
No
DTC troubleshooting completed.


Vehicles with four cooling fan relays

DTC P0481:00

Cooling fan relay No.4 control circuit malfunction
DETECTION CONDITION
•  The PCM monitors the cooling fan relay No.4 control signal voltage and current. If the following conditions are met, the PCM determines that there is the cooling fan relay No.4 control circuit problem.
―  The PCM turns the cooling fan relay No.4 off, but the voltage of the cooling fan relay No.4 control signal remains low for 5 s.
―  The PCM turns the cooling fan relay No.4 on, but the current of the cooling fan relay No.4 control signal remains high for 5 s.
Diagnostic support note
•  This is a continuous monitor (other).
•  The MIL does not illuminate.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Cooling fan relay No.4 malfunction
•  Short to ground or open circuit in cooling fan relay No.4 power supply circuit
―  Short to ground in wiring harness between ENGINE IG 15 A fuse and cooling fan relay No.4 terminal E
―  ENGINE IG 15 A fuse malfunction
―  Open circuit in wiring harness between ignition switch*1/relay block*2 and cooling fan relay No.4 terminal E
•  Short to ground in wiring harness between cooling fan relay No.4 terminal A and PCM terminal 1V
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between cooling fan relay No.4 terminal A and PCM terminal 1V
•  Open circuit in wiring harness between cooling fan relay No.4 terminal A and PCM terminal 1V
•  PCM malfunction

*1  :Vehicles without advanced keyless entry and push button start system
*2  :Vehicles with advanced keyless entry and push button start system

Diagnostic procedure

STEP

INSPECTION

ACTION
1
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.
2
INSPECT COOLING FAN RELAY NO.4
•  Switch the ignition to off.
•  Remove the cooling fan relay No.4.
•  Inspect the cooling fan relay No.4.
•  Is there any malfunction?
Yes
Replace the cooling fan relay No.4, then go to Step 8.
No
Go to the next step.
3
INSPECT COOLING FAN RELAY NO.4 POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT
•  Cooling fan relay No.4 is removed.
•  Switch the ignition to ON (engine off).
•  Measure the voltage at the cooling fan relay No.4 terminal E (wiring harness-side).
•  Is the voltage B+?
Yes
Go to the next step.
No
Inspect the ENGINE IG 15 A fuse.
•  If the fuse is melt:
―  Repair or replace the wiring harness for a possible short to ground.
―  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 8.
4
INSPECT COOLING FAN RELAY NO.4 SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Cooling fan relay No.4 is removed.
•  Switch the ignition to off.
•  Inspect for continuity between cooling fan relay No.4 terminal A (wiring harness-side) and body ground.
•  Is there continuity?
Yes
If the short to ground circuit could be detected:
•  Repair or replace the wiring harness for a possible short to ground.
If the short to ground circuit could not be detected:
•  Replace the PCM (short to ground in the PCM internal circuit).
Go to Step 8.
No
Go to the next step.
5
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 8.
No
Go to the next step.
6
INSPECT COOLING FAN RELAY NO.4 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Cooling fan relay No.4 is removed.
•  PCM connector is disconnected.
•  Switch the ignition to ON (engine off).
•  Measure the voltage at the cooling fan relay No.4 terminal A (wiring harness-side).
•  Is there any voltage?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 8.
No
Go to the next step.
7
INSPECT COOLING FAN RELAY NO.4 SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  Cooling fan relay No.4 is removed.
•  PCM connector is disconnected.
•  Switch the ignition to off.
•  Inspect for continuity between cooling fan relay No.4 terminal A (wiring harness-side) and PCM terminal 1V (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.
8
VERIFY DTC TROUBLESHOOTING 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 same DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI].)
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 2.0 DISI].)
No
DTC troubleshooting completed.