Toyota RAV4 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.
- Check any other dtcs output (in addition to dtc p0116)
- Connect the intelligent tester to the dlc3.
- Turn the ignition switch on.
- Turn the tester on.
- Select the following menu items: diagnosis / enhanced ii / dtc info / current codes.
- Read the dtc.
- Inspect thermostat
- Remove the thermostat (see page co-15).
- 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.
- Reinstall the thermostat (see page co-15).
Engine coolant temperature circuit
Description
A thermistor, whose resistance value varies according to the ect, is built
into the engine coolant
temperature (ect) sensor.
The structure of the sensor and its connection to th ...
Throttle / pedal position sensor / switch "A"
Hint:
These dtcs relate to the throttle position (tp) sensor.
Description
The tp sensor is mounted on the throttle body, and detects the opening angle
of the throttle valve. This
sensor is a ...
Other materials:
Operation check
Check key reminder warning system
Check that the key reminder warning buzzer
sounds.
With the driver side door closed, insert the key
into the ignition key cylinder and then turn the
ignition switch to lock or acc.
Check that the buzzer sounds intermittently
when the driver ...
Fail-safe chart
Fail-safe chart
This function minimizes the loss of the ect functions
when a malfunction occurs in a sensor or solenoid.
Automatic transmission fluid (atf) temperature
sensor:
when the atf temperature sensor has a
malfunction, o/d up-shift is prohibited
Counter gear speed sensor n ...
Removal
Drain engine coolant (see page co-6)
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove no. 1 Engine cover
Remove ...