Sfi System - P0125

Brand:

Toyota

Model Name:

4Runner GRN210 215 UZN210 215

Manual:

Repair Manual

Section:

2Uz-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Monitor description

  3. Monitor strategy

  4. Typical enabling conditions

  5. Typical malfunction thresholds

  6. Wiring diagram

  7. Inspection procedure

  8. Check any other dtcs output (in addition to dtc p0125)

  9. Inspect thermostat

  10. Check cooling system

DTC P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control


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DESCRIPTION

Refer to DTC P0115 (Click here).

DTC No.
DTC Detection Condition
Trouble Area
P0125
(1) If THW or THA is less than -6.6°C (20°F) at engine start and 20 minutes or more after starting engine, engine coolant temperature sensor value is 20°C (68°F) or less (2 trip detection logic)
(2) If THW and THA is between -6.6°C (20°F) and 10°C (50°F) at engine start, 129 seconds or more after starting engine and engine coolant temperature sensor value is 20°C (68°F) or less (2 trip detection logic)
(3) If THW and THA are greater than 10°C (50°F) at engine start and 77 seconds or more after starting engine, engine coolant temperature sensor value is 20°C (68°F) or less (2 trip detection logic)
  1. Cooling system
  2. Engine coolant temperature sensor
  3. Thermostat

MONITOR DESCRIPTION

The Engine Coolant Temperature (ECT) sensor is used to monitor the temperature of the engine coolant. The resistance of the sensor varies with the actual coolant temperature. The ECM applies a voltage to the sensor and the varying resistance of the sensor causes the signal voltage to vary. The ECM monitors the ECT signal voltage after engine start-up. If the sensor still reports that the engine is not warmed up enough for closed-loop fuel control after sufficient time has passed, the ECM interprets this as a fault in the sensor or cooling system and sets a DTC.
Example:
The ECT is 0°C (32°F) at engine start. After 77 seconds running time, the ECT sensor still indicates that the engine is not warm enough to begin air-fuel ratio feedback control of the air-fuel ratio. The ECM interprets this as a fault in the sensor or cooling system and will set a DTC.

MONITOR STRATEGY


Related DTCs
P0125: Insufficient engine coolant temperature for closed-loop fuel control
Required Sensors/Components (Main)
Thermostat, Cooling system
Required Sensors/Components (Related)
Engine coolant temperature sensor, Mass air flow meter
Frequency of Operation
Continuous
Duration
77 seconds: -8.34°C (16.98°F) or more
129 seconds: -19.45 to -8.34°C (-3.01 to 16.98°F)
1200 seconds: Less than -19.45°C (-3.01°F)
MIL Operation
2 driving cycles
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


The monitor will run whenever this DTC is not present
P0100 - P0103 (MAF sensor)
P0110 - P0113 (IAT sensor)
P0115 - P0118 (ECT sensor)
Engine
Running
Fuel cut
OFF

TYPICAL MALFUNCTION THRESHOLDS


Time until "engine coolant temperature" detection temperature reaches feedback start temperature
-
When the temperature at the time of engine starting is -8.34°C (17°F) or more
Engine coolant temperature is less than "closed-loop enable temperature" when 77 sec. or more after engine start
When the temperature at the time of engine starting is -19.45 to -8.34°C (-3 to 17°F)
Engine coolant temperature is less than "closed-loop enable temperature" when 129 sec. or more after engine start
When the temperature at the time of engine starting is -19.45°C (-3°F) or less
Engine coolant temperature is less than "closed-loop enable temperature" when 20 min. or more after engine start

WIRING DIAGRAM

Refer to DTC P0115 (Click here).

INSPECTION PROCEDURE

HINT:
  1. If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, an ECT sensor circuit may be open or short. Perform the troubleshooting of DTC P0115, P0117 or P0118 first.
  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 DTC P0125)

  1. Connect the intelligent tester to the DLC3 with CAN VIM.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

  1. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

  1. Read the DTCs.

    Result:

    Display (DTC Output)
    		Proceed to
    P0125
    		A
    P0125 and other DTCs
    		B
    HINT:
    If any other codes besides P0125 is output, perform the troubleshooting for those codes first.


Bnext
GO TO RELEVANT DTC CHART
A
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2.INSPECT THERMOSTAT

  1. Remove the thermostat (Click here).

  1. Check the valve opening temperature of the thermostat (Click here).

    OK:
    Valve opening temperature is 80 to 84°C (176 to 183°F)
    HINT:
    Also check that the valve is completely closed below the opening temperature shown above.

  1. Reinstall the thermostat (Click here).



NGnext
REPLACE THERMOSTAT
OK
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3.CHECK COOLING SYSTEM

  1. Check that there is a defect in the cooling system which causes overcool, such as abnormal radiator fan operation, modified cooling system and so on.



NGnext
REPAIR OR REPLACE COOLING SYSTEM
OK
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REPLACE ENGINE COOLANT TEMPERATURE SENSOR