SFI SYSTEM(w/ Canister Pump Module), Diagnostic DTC:P0125

DTC Code DTC Name
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control

DESCRIPTION

Refer to DTC P0115.

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DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0125

Insufficient Coolant Temperature for Closed Loop Fuel Control

The engine coolant temperature does not reach the closed loop enabling temperature for 20 minutes (this period varies with the engine coolant temperature at engine start) (2 trip detection logic).

  • Cooling system

  • Engine coolant temperature sensor

  • Thermostat

Comes on

DTC stored

MONITOR DESCRIPTION

The resistance of the engine coolant temperature sensor varies in proportion to the actual engine coolant temperature. The ECM supplies a constant voltage to the sensor and monitors the signal output voltage of the sensor. The signal output voltage varies according to the changing resistance of the sensor. After the engine is started, the engine coolant temperature is monitored by this signal. If the engine coolant temperature sensor indicates that the engine is not yet warm enough for closed loop fuel control, despite a specified period of time having elapsed since the engine was started, the ECM interprets this as a malfunction in the sensor or cooling system and stores the DTC.

Example:

When the engine coolant temperature is 5°C (41°F) at engine start: After approximately 50 seconds of running time, the engine coolant temperature sensor still indicates that the engine is not warm enough to begin closed loop fuel (air fuel ratio feedback) control. The ECM interprets this as a malfunction in the sensor or cooling system and stores the DTC.

MONITOR STRATEGY

Frequency of Operation

Once per driving cycle

CONFIRMATION DRIVING PATTERN

  1. Leave the vehicle outside overnight.

  2. Connect the GTS to the DLC3.

  3. Turn the engine switch on (IG) and turn the GTS on.

  4. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.

  5. Check that the engine coolant temperature is 10°C (50°F) or less.

  6. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  7. Turn the engine switch off and wait for at least 30 seconds.

  8. Turn the engine switch on (IG) and turn the GTS on.

  9. Start the engine.

  10. Wait 21 minutes or more.

  11. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

  12. Read the pending DTCs.

    Tip:

    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  14. Input the DTC: P0125.

  15. Check the DTC judgment result.

    GTS Display

    Description

    NORMAL

    • DTC judgment completed

    • System normal

    ABNORMAL

    • DTC judgment completed

    • System abnormal

    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions

    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
    Tip:

    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

WIRING DIAGRAM

Refer to DTC P0115.

Click here

CAUTION / NOTICE / HINT

Tip:

  • If any of DTCs P0115, P0117 or P0118 are output simultaneously with DTC P0125, the engine coolant temperature sensor may have an open or a short circuit. Troubleshoot those DTCs first.

  • Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION DTC P0125)

    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P0125 is output

      A

      DTC P0125 and other DTCs are output

      B
      Tip:

      If any DTCs other than P0125 are output, troubleshoot those DTCs first.

    B

    GO TO DTC CHART

    Click here

    A

  2. INSPECT THERMOSTAT

    1. Inspect the thermostat opening temperature.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE THERMOSTAT

    Click here

    OK

  3. CHECK COOLING SYSTEM

    1. Check for defects in the cooling system that might cause the system to be too cold, such as abnormal cooling fan operation or any modifications.

      Tip:

      Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.

      Click here

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ENGINE COOLANT TEMPERATURE SENSOR

    Click here

    NG

    REPAIR OR REPLACE COOLING SYSTEM