Inspection Procedure

WARNING: This page is about a different car, the 2008 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

Read freeze frame data using Techstream. 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 P0128)

Connect Techstream to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Trouble Code.

Read DTCs.

Result

RESULT REFERENCE

Display (DTC Output)	Proceed To
P0128	A
P0128 and other DTCs	B

HINT:

If any DTCs other than P0128 are output, troubleshoot those DTCs first.

B: GO TO DTC CHART

A: Go to Next Step

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.
NG: REPAIR OR REPLACE COOLING SYSTEM

OK: Go to Next Step
INSPECT THERMOSTAT
1. Remove the thermostat (see REMOVAL ).
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.
3. Reinstall the thermostat (see INSTALLATION ).
NG: REPLACE THERMOSTAT

OK: REPLACE ECM