Toyota RAV4 manuals

Toyota RAV4 Service Manual: Coolant thermostat (coolant temperature below thermostat regulating temperature)

Toyota RAV4 Service Manual / 2Az-fe engine mechanical / Sfi system / Diagnostic trouble code chart / Coolant thermostat (coolant temperature below thermostat regulating temperature)

Toyota RAV4. Coolant thermostat (coolant temperature below thermostat regulating temperature)


Hint:

This dtc relates to the thermostat.

Description

This dtc is set when the engine coolant temperature (ect) does not reach 75°c (167°f) despite sufficient engine warm-up time having elapsed.

Toyota RAV4. Coolant thermostat (coolant temperature below thermostat regulating temperature)


Monitor description

Toyota RAV4. Monitor description


The ecm estimates the ect based on the starting temperature, engine loads, and engine speeds. The ecm then compares the estimated temperature with the actual ect. When the estimated ect reaches 75°c (167°f), the ecm checks the actual ect. If the actual ect is less than 75°c (167°f), the ecm interprets this as a malfunction in the thermostat or the engine cooling system and sets the dtc.

Monitor strategy



Typical enabling conditions

Toyota RAV4. Typical enabling conditions


Typical malfunction thresholds

Toyota RAV4. Typical malfunction thresholds


Inspection procedure

Hint:

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 p0128)

  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 obd ii / dtc info / current codes.
  5. Read dtcs.

Toyota RAV4. Check any other dtcs output (in addition to dtc p0128)


Hint:

If any dtcs other than p0128 are output, troubleshoot those dtcs first.



  1. Check cooling system

  1. Check for defects in the cooling system that might cause the system to be too cold, such as abnormal radiator fan operation or any modifications.



  1. Inspect thermostat

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

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

Hint:

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

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

 


Insufficient coolant temperature for closed loop fuel control
Description Refer to dtc p0115 (see page es-105). Monitor description The resistance of the ect sensor varies in proportion to the actual ect. The ect supplies a constant voltage to the ...

Oxygen sensor circuit
Description In order to obtain a high purification rate of the carbon monoxide (co), hydrocarbon (hc) and nitrogen oxide (nox) components in the exhaust gas, a twc is used. For the most effici ...

Other materials:

Diagnosis system
Check dlc3 The ecm uses iso 15765-4 for communication. The terminal arrangement of the dlc3 complies with sae j1962 and matches the iso 15765-4 format. If the result is not as specified, the dlc3 may have a malfunction. Repair or replace the harness and connector. Hint: Conn ...

Removal
Notice: Do not heat the vehicle body, emblem and name plate excessively. Hint: When removing the emblem and name plate, heat the vehicle body, emblem and name plate using a heat light. Standard heating temperature Remove no. 1 Back door emblem assembly Put protective tape aroun ...

Using the aux port
This port can be used to connect a portable audio device and listen to it using the vehicle’s speakers. Open the cover and connect the portable audio device. Press the “media” button repeatedly until “aux” is displayed. Silencing a sound Press (mute). To cancel, p ...

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