Tachometer Malfunction

METER: METER / GAUGE SYSTEM: Tachometer Malfunction

Tachometer Malfunction

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE OF TECHSTREAM
(a) Warm up the engine.
(b) Ignition switch off.
(c) Connect Techstream to the DLC3.
(d) Turn the ignition switch to the ON position.
(e) Turn the tester ON.
(f) Enter following menus:
(1) for Engine and ECT: Powertrain / Engine and ECT / Data List.
(g) Check values by referring to the table below.

Engine and ETC:





OK:
Engine speed displayed on the tester is almost the same as the actual engine speed.
NG -- GO TO SFI SYSTEM
OK -- Continue to next step.
2. INSPECT COMBINATION METER ASSEMBLY
(a) Check the input signal wave form.





(1) Remove the combination meter with connector still connected.
(2) Connect the oscilloscope to terminal C11-27 and body ground.
(3) Start the engine.





(4) Check the signal wave form 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
3. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)





(a) Disconnect the C11 and E6 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