Tachometer Malfunction

METER: METER / GAUGE SYSTEM: Tachometer Malfunction

Tachometer Malfunction

DESCRIPTION

When turn the ignition switch to the ON position, the combination meter assembly communicates with the ECM by the direct line.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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





(1) Remove the combination meter assembly with the connector(s) still connected.
(2) Connect the oscilloscope to the terminals C11-13 (TM IN) and body ground.
(3) Start the engine.





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






OK:
The waveform is displayed as shown in the illustration.
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