METER / GAUGE SYSTEM Engine Coolant Temperature Gauge Malfunction

DESCRIPTION

In this circuit, the combination meter assembly receives engine coolant temperature signals from the ECM using CAN communication lines. The combination meter assembly displays an engine coolant temperature that is calculated based on the data received from the ECM.

WIRING DIAGRAM


*1	CAN Line
*2	Combination Meter Assembly

CAUTION / NOTICE / HINT

Tech Tips

If there is an open or short in the engine coolant temperature sensor circuit, an SFI system DTC is output. If output, perform troubleshooting on the SFI system first.

PROCEDURE

CHECK CAN COMMUNICATION SYSTEM

Check for DTCs Click here.

Result
Result	Proceed to
CAN communication system DTC is not output	A
CAN communication system (for LHD with Central Gateway ECU) DTC is output	B
CAN communication system (for LHD without Central Gateway ECU) DTC is output	C
CAN communication system (for RHD with Central Gateway ECU) DTC is output	D
CAN communication system (for RHD without Central Gateway ECU) DTC is output	E

GO TO CAN COMMUNICATION SYSTEM Click here

PERFORM ACTIVE TEST USING GTS (COOLANT TEMP)

Operate the GTS according to the display and select Active Test.

Combination Meter
Tester Display	Test Part	Control Range	Diagnostic Note
Water Temperature Meter Operation	Engine coolant temperature receiver gauge	LOW, NORMAL or HIGH	Perform the test with the vehicle stopped and engine idling.

Tech Tips

Confirm that the vehicle is stopped and the engine is idling.

OK
Needle indication is normal.

REPLACE COMBINATION METER ASSEMBLY Click here

READ VALUE USING GTS (COOLANT TEMPERATURE)

Operate the GTS according to the display and select Data List.

Combination Meter
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Coolant Temperature	Engine coolant temperature/Min.: -40 (-40), Max.: 140 (284)	After warming up: 80 to 105 (176 to 221)	Unit: °C (°F) If the value is -40 (-40): The sensor circuit is open. If the value is 140 (284): The sensor circuit is shorted.

OK
Coolant temperature displayed on the GTS is between 80°C (176°F) and 95°C (203°F) after warming up.

Result
Result	Proceed to
OK	A
NG	B

REPLACE COMBINATION METER ASSEMBLY Click here

READ VALUE USING GTS (ENGINE COOLANT)

Operate the GTS according to the display and select Data List.

Engine*1, *2, *3
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Coolant Temp	Engine coolant temperature: Min.: -40°C, Max.: 140°C	80 to 100°C (176 to 212°F): After warming up	If the value is -40°C (-40°F), the sensor circuit is open. If the value is 140°C (284°F), the sensor circuit is shorted.

Engine*4
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Coolant Temp	Engine coolant temperature/ Min.: -40°C, Max.: 140°C	After warming up engine: 75 to 90°C (167 to 194°F)	If the value is -40°C (-40°F) or 140°C (284°F), the sensor circuit is open or shorted. After a long soak, the coolant temperature, intake air temperature, and ambient air temperature are approximately equal.

*1: for 1GR-FE
*2: for 1UR-FE
*3: for 3UR-FE
*4: for 1VD-FTV

OK
Engine coolant temperature value displayed on the GTS is almost the same as actual engine coolant temperature.

Result
Result	Proceed to
OK	A
NG (for Gasoline)	B
NG (for Diesel)	C

Tech Tips

*1: Refer to SFI System:

for 1GR-FE Click here
for 1UR-FE Click here
for 3UR-FE (w/ Secondary Air Injection System) Click here
for 3UR-FE (w/o Secondary Air Injection System) Click here

*2: Refer to ECD System:

for 1VD-FTV (w/ DPF) Click here
for 1VD-FTV (w/o DPF) Click here

GO TO SFI SYSTEM (*1)

GO TO ECD SYSTEM (*2)

CHECK COMBINATION METER ASSEMBLY

Temporarily replace the combination meter with a new one Click here.

Check that the operation of the combination meter returns to normal Click here.

OK
Operation of combination meter returns to normal.

Result
Result	Proceed to
OK	A
NG (for 1GR-FE)	B
NG (for 1UR-FE)	C
NG (for 3UR-FE)	D
NG (for 1VD-FTV)	E

END (COMBINATION METER IS DEFECTIVE)

REPLACE ECM Click here