Inspection Procedure

HINT:

• If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, the engine coolant temperature sensor circuit may be open or short. Perform the troubleshooting of 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. Are there any other codes (besides DTC P0125) being output? 

   PREPARATION: 

   1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   2. Turn the ignition switch ON and push the hand-held tester or the OBD II scan tool main switch ON.
   3. When using hand-held tester, enter the following menus: DIAGNOSIS/ENHANCED OBD II/DTC INFO/CURRENT CODES.

   CHECK: 

   Read the DTC using the hand-held tester or OBD II scan tool.

   RESULT: 

   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.

   B: Go to relevant DTC chart (See  DIAGNOSTIC TROUBLE CODE CHART  ). 

   A: Go to next step 

2. Check thermostat (See  INSPECTION  ). 

   NG: Replace thermostat (See  REMOVAL  ). 

   OK: Go to next step. 

3. Check cooling system. 

   CHECK: 

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

   NG: Repair or replace cooling system. 

   OK: Replace engine coolant temperature sensor (See  ENGINE COOLANT TEMPERATURE (ECT) SENSOR  ).