Inspection Procedure

HINT:

• If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, engine coolant temperature sensor circuit may be open or short. Perform troubleshooting on DTC P0115, P0117 or P0118 first.
• Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0125) 
   1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   2. Turn the ignition switch to ON and turn the hand-held tester or the OBD II scan tool ON.
   3. Select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   4. Read DTCs.

      Result: 

      Fig 1: DTC Output Result Table

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT: If any other codes besides P0125 are output, perform troubleshooting for those DTCs first.

   B: GO TO RELEVANT DTC CHART (See  DIAGNOSTIC TROUBLE CODE CHART  ) 

   A: GO TO NEXT STEP. 

2. INSPECT THERMOSTAT (See  INSPECTION  ) 

   NG: REPLACE THERMOSTAT 

   OK: GO TO NEXT STEP. 

3. CHECK COOLING SYSTEM 
   1. Check that there is no defect in the cooling system which causes overcool, such as abnormal radiator fan operation and modified cooling system.

   NG: REPAIR OR REPLACE COOLING SYSTEM 

   OK: GO TO NEXT STEP. 

   REPLACE ENGINE COOLANT TEMPERATURE SENSOR