Troubleshooting
P0115 - Engine Coolant Temp Circuit MalfunctionCIRCUIT DESCRIPTION
DTC Detecting Condition:
A thermistor built into the water temperature sensor changes the resistance value according to the water temperature.
The structure of the sensor and connection to the ECM is the same as the ones of the air temperature sensor.
HINT: After confirming DTC P0115, use the OBDII scan tool or TOYOTA hand-held tester to confirm the engine coolant temperature from the CURRENT DATA.
Wiring Diagram:
Step 1 - 3:
Step 4 - 5:
INSPECTION PROCEDURE
HINT:
- If DTCs P0100, P0101, P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
- Read freeze frame data using the TOYOTA hand-held tester or OBDII scan tool, as freeze frame data records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
CHECK FOR INTERMITTENT PROBLEMS
TOYOTA hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection logic and the sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
1. Clear the DTC.
2. Set the check mode.
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.