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Home >> Lexus >> 2005 >> SC 430 >> Repair and Diagnosis >> Engine Performance >> System >> SFI System - Diagnostics >> DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control >> Inspection Procedure
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Inspection Procedure

HINT:

  1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0125) 
    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch ON and turn the hand-held tester ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBDII / DTC INFO / CURRENT CODES.

    Result: 

    RESULT DESCRIPTION

    Display (DTC Output) Proceed to
    Only P0125 are output A
    P0125 and other DTCs are output B

    HINT:

    If any other codes besides P0125 is output, perform the troubleshooting for those codes first.

    1. B: Go to RELEVANT DTC TABLE (See  DIAGNOSTIC TROUBLE CODE TABLE   ) 
    2. A: Go to next step. 
  2. INSPECT THERMOSTAT (See  INSPECTION  ) 
    1. Check the valve opening temperature of the thermostat.

      OK: Valve opening temperature is 80 to 84°C (176 to 183°F) 

    HINT:

    Also check that the valve is completely closed under opening temperature as above.

    1. NG: REPLACE THERMOSTAT (See  REPLACEMENT  ) 
    2. OK: Go to next step. 
  3. CHECK COOLING SYSTEM (See  COOLING SYSTEM  ) 
    1. Check for defects in the cooling system that might cause the system to be too cold, such as abnormal radiator fan operation or a modified cooling system.
    1. NG: REPAIR OR REPLACE COOLING SYSTEM 
    2. OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR