Toyota RAV4 (XA40) 2013-2018 Service Manual: Engine coolant temperature circuit range / performance problem

Description

Refer to dtc p0115 (see page es-105).

Monitor description

Engine coolant temperature (ect) sensor cold start monitor

When a cold engine start is performed and then the engine is warmed up, if the ect sensor value does not change, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the mil is illuminated and a dtc is set.

Ect sensor soak monitor

After a warmed up engine is started, if the ect sensor value does not change when the engine is stopped and then the next cold engine start is performed, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the mil is illuminated and a dtc is set.

Monitor strategy

Typical enabling conditions

typical malfunction thresholds

Component operating range

Inspection procedure

Hint:

• If any of dtcs p0115, p0117, p0118 or p0125 are set simultaneously with dtc p0116, the ect sensor may have an open or a short circuit. Troubleshoot those dtcs first.
• Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, 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 any other dtcs output (in addition to dtc p0116)

1. Connect the intelligent tester to the dlc3.
2. Turn the ignition switch on.
3. Turn the tester on.
4. Select the following menu items: diagnosis / enhanced ii / dtc info / current codes.
5. Read the dtc.

2. Inspect thermostat

1. Remove the thermostat (see page co-15).
2. Measure the valve opening temperature of the thermostat.

Standard value: 80°c to 84°c (176°f to 183°f)

Hint:

In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.

3. Reinstall the thermostat (see page co-15).