Tachometer Malfunction

METER: METER / GAUGE SYSTEM: Tachometer Malfunction

Tachometer Malfunction

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (ENGINE SPEED)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream ON.
(d) On the Techstream, select the following menu items: Powertrain / Engine / Data List / Engine Rpm.
(e) Read the value displayed on the Techstream.
OK:
Engine speed displayed on the Techstream is almost the same as the actual engine speed.
NG -- GO TO ENGINE CONTROL SYSTEM
OK -- Continue to next step.
2. INSPECT COMBINATION METER ASSEMBLY





(a) Inspect the combination meter using an oscilloscope.
(b) While the engine is running, check the waveform between the terminals of the C9 combination meter connector and body ground.
Standard:





OK -- REPLACE COMBINATION METER ASSEMBLY
NG -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)





(a) Disconnect the C9 combination meter connector.
(b) Disconnect the E7 ECM connector.
(c) Measure the resistance.
Standard Resistance:





(d) Reconnect the ECM connector.
(e) Reconnect the combination meter connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM