Cooling Fan Control System Inspection
- Connect the M-MDS to the DLC-2.
- Verify that DTC P0480, P0481 or P0482 is not displayed.
- If DTC P0480, P0481 or P0482 are displayed, perform DTC inspection. (See DTC TABLE [13B-MSP] .)
- Start the engine and run it at idle with ECT PID is below 94°C {201°F} .
- Verify that both cooling fan No. 1 and No. 2 do not operate when the A/C and fan switch is off.
- If the cooling fan No. 1 and No. 2 operate low speed, inspect for following;
- Cooling fan relay No. 1 (stuck close)
- Cooling fan relay No. 5 (stuck close)
- If the cooling fan No. 1 does not operate but the cooling fan No. 2 operates middle speed, inspect for following;
- Cooling fan relay No. 3 (stuck close)
- Cooling fan relay No. 4 (stuck close)
- If the cooling fan No. 1 and No. 2 operate low speed, inspect for following;
- Start the engine and run it at idle with the ECT is 97-100°C {207-212°F} .
- Verify that both cooling fan No. 1 and No. 2 operate low speed.
- If the operation can not be verified, inspect the following points according to cooling fan conditions.
COOLING FAN CONDITION REFERENCE CHARTCooling fan condition Inspection point Cooling fan No. 1 Cooling fan No. 2 Stop Stop - Cooling fan relay No. 1 (stuck open)
- Cooling fan motor No. 1 (internal circuit open)
- Cooling fan motor No. 2 (internal circuit open)
- Open circuit in wiring harness between battery positive post and cooling fan motor No. 1
- Open circuit in wiring harness between cooling fan motor No. 1 and cooling fan motor No. 2 through cooling fan relay No. 2
- Open circuit in wiring harness between cooling fan motor No. 2 and GND
Middle speed Stop - Cooling fan relay No. 2 (stuck close)
Stop Middle speed - Cooling fan relay No. 4 (stuck close)
- Start the engine and run it idle with the ECT is 101-107°C {214-224°F} .
- Verify that both cooling fan relay No. 1 and No. 2 operate middle speed.
- If the operation can not be verified, inspect the following points according to cooling fan conditions.
COOLING FAN CONDITION REFERENCE CHARTCooling fan condition Inspection point Cooling fan No. 1 Cooling fan No. 2 Low speed High speed - Cooling fan relay No. 2 (stuck open)
Stop Middle speed - Open circuit in wiring harness between cooling fan relay No. 2 and GND
Middle speed Stop - Cooling fan relay No. 3 (stuck open)
- Open circuit in wiring harness between battery positive post and cooling fan motor No. 2 through cooling fan relay No. 3
Middle speed Low speed - Cooling fan motor No. 2 (internal circuit open)
Low speed Middle speed - Cooling fan motor No. 1 (internal circuit open)
High speed Middle speed - Cooling fan relay No. 5 (stuck close)
Middle speed High speed - Cooling fan relay No. 4 (stuck close)
- Stop the engine.
- Disconnect the ECT sensor connector.
- Turn the ignition switch to ON position.
- Verify that both cooling fan No. 1 and No. 2 operate high speed.
- If the operation can not be verified, inspect the following points according to cooling fan conditions.
COOLING FAN CONDITION REFERENCE CHARTCooling fan condition Inspection point Cooling fan No. 1 Cooling fan No. 2 Middle speed High speed - Cooling fan relay No. 2 (stuck open)
- Open circuit in wiring harness between battery positive post and cooling fan motor No. 1 through cooling fan relay No. 5
- Cooling fan motor No. 1 (internal circuit open)
High speed Middle speed - Cooling fan relay No. 4 (stuck open)
- Open circuit in wiring harness between battery positive post and cooling fan motor No. 2 through cooling fan relay No. 2
- Cooling fan motor No. 2 (internal circuit open)
- Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [13B-MSP] .)