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DTC    P148F    Engine Coolant Pump Over Revolution

for Preparation Click here


DESCRIPTION

The ECM controls the engine water pump assembly by calculating the necessary amount of coolant flow based on engine coolant temperature, engine speed and vehicle speed information. The speed of the engine water pump assembly is controlled steplessly using a duty cycle signal sent from the ECM. This optimal control enhances warm-up performance and reduces cooling losses, thus reducing the specific fuel consumption of the engine. The ECM monitors the speed of the engine water pump assembly and sets a DTC when it determines that the engine water pump assembly rotates excessively based on the fact that the actual speed is higher than the target for a certain amount of time. (However, the engine warning light will not illuminate.)

HINT:
The engine coolant temperature indicator light built into the combination meter assembly illuminates or blinks when the coolant temperature becomes 117°C (243°F) or higher.


DTC No.
DTC Detection Condition
Trouble Area
P148F
When both of the following conditions are met for 5 seconds or more (1 trip detection logic):
  1. Engine water pump assembly duty ratio is 85% or more.
  2. Actual engine water pump assembly speed has been more than the target by a certain amount.
  1. Lack of engine coolant
  2. Engine coolant leak
  3. Engine water pump assembly

INSPECTION PROCEDURE

HINT:
  1. DTC P148F may be stored if the engine has continuously run with insufficient engine coolant. If the engine coolant is sufficient and DTC P148F recur when the vehicle is brought to the workshop, confirm whether engine coolant was added after the vehicle had been driven with insufficient engine coolant.
  2. Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P148F)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read the DTCs.
    Result 
    Result
    		Proceed to
    DTC P148F is output
    		A
    DTC P148F and other DTCs are output
    		B

    HINT:
    If any DTCs other than P148F are output, troubleshoot those DTCs first.



B
GO TO DTC CHART (Click here)
A


2.CHECK RADIATOR RESERVOIR TANK ASSEMBLY (ENGINE COOLANT LEVEL)

  1. Check that the engine coolant level is between the FULL and LOW lines .

    Result 
    Result
    		Proceed to
    Engine coolant level is below the LOW line
    		A
    Engine coolant level is above the LOW line
    		B



B
Go to step 6
A


3.CHECK FOR COOLANT LEAKS

  1. Check the areas around the engine and heater for coolant leaks .

    OK:
    No leaks.

    HINT:
    If the engine oil is cloudy during the engine oil level gauge check, it means that coolant has entered the engine lubrication system.



NG
Go to step 5
OK


4.ADD ENGINE COOLANT

  1. Fill the reservoir tank up to the FULL line with engine coolant.

    NOTICE:
    1. Make sure to bleed the air from the engine coolant after refill (Click here).
    2. Make sure not to add engine coolant when the engine is hot.



NEXT
Go to step 6

5.REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

  1. Repair any coolant leaks.

    HINT:
    Add coolant and perform air bleeding after repair (Click here).


NEXT


6.CLEAR DTC

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Clear the DTCs (Click here).


NEST


7.INSPECT ENGINE WATER PUMP ASSEMBLY

HINT:
Perform repair indoors or in a workshop.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Put the engine in inspection mode (maintenance mode) (Click here).

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp and Elec Water Pump Spd.

    HINT:
    Display the Data List diagram.

  1. Start the engine.

  1. Idle the engine for about 20 minutes and check Coolant Temp, Elec Water Pump Spd using the tester, and check the cooling fans.

    Result 
    Result
    		Proceed to
    Either of the following conditions is met:
    1. The engine coolant temperature becomes 95°C (203°F) or higher and the engine water pump assembly performs intermittent operation (5 second pause after 25 second operation).
    2. The engine water pump assembly do not start operating even after the engine coolant temperature becomes 95°C (203°F) or higher.*1, *2
    		A
    The cooling fans start operating after the engine coolant temperature becomes 95°C (203°F) or less and decrease in the engine coolant temperature is observed.*3
    		B

    HINT:
    1. *1: Be careful when the cooling fans do not start operating even after the engine coolant temperature becomes 95°C (203°F) or higher because the engine coolant temperature increases rapidly. (Make sure to stop the engine if the engine coolant temperature becomes 105°C (221°F) or higher.)
    2. *2: If the ECM voltage is 14 V or higher and the engine water pump assembly is run excessively due to insufficient coolant etc., the water pump motor speed will exceed 5000 rpm. Enter the following menus to check the voltage of the ECM: Powertrain / Engine and ECT / Data List / Battery Voltage (Click here).
    3. *3: When the engine is warmed up, the cooling fans operate and the engine coolant temperature will decrease. After the cooling fans begin operating, the engine coolant temperature will stabilize between 88 to 95°C (190 to 203°F).



B
END
A


8.REPLACE ENGINE WATER PUMP ASSEMBLY

  1. Replace the engine water pump assembly (Click here).


NEXT


9.ADD ENGINE COOLANT

  1. Fill the reservoir tank up to the FULL line with engine coolant.

    NOTICE:
    1. Make sure to bleed the air from the engine coolant after refill (Click here).
    2. Make sure not to add engine coolant when the engine is hot.


NEXT


10.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

HINT:
Perform repair indoors or in a workshop.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the tester on.

  1. Clear the DTCs (Click here).

  1. Put the engine in inspection mode (maintenance mode) (Click here).

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Coolant Temp and Elec Water Pump Spd.

  1. Idle the engine for about 20 minutes and check Coolant Temp, Elec Water Pump Spd using the tester, and check the cooling fans.

    Result:
    The cooling fans start operating after the engine coolant temperature becomes 95°C (203°F) or less and decrease in the engine coolant temperature is observed.


NEXT

END