Engine Coolant Temperature Receiver Gauge Malfunction

METER: METER / GAUGE SYSTEM: Engine Coolant Temperature Receiver Gauge Malfunction

Engine Coolant Temperature Receiver Gauge Malfunction

WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: If there is an open or short in the engine coolant temperature sensor circuit, the ECM outputs DTCs. Perform troubleshooting with the "SFI System" SFI System.

PROCEDURE

1. INSPECT COMBINATION METER ASSEMBLY
(a) Check the input signal waveform.





(1) Remove the combination meter assembly with connectors still connected.
(2) Connect the oscilloscope to the terminal C11-5 (TEMP COMMUNICATION INPUT) and body ground.
(3) Start the engine.





(4) Check the signal waveform according to the condition(s) in the table below.





HINT: As the coolant temperature rises, the period "A" shown in the illustration becomes longer.

Reference:






NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
OK -- REPLACE COMBINATION METER ASSEMBLY
2. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
(a) Disconnect the C11 and E8 connectors.





(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM