Tachometer Malfunction

METER: METER / GAUGE SYSTEM: Tachometer Malfunction
- Tachometer Malfunction

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (ENGINE SPEED)

(a) Warm up the engine.

(b) Turn the ignition switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the tester on.

(f) Enter the following menus: Powertrain / Engine and ECT / Data List.

(g) According to the display on the tester, read the Data List.

Engine and ECT





*1: for 2TR-FE

*2: for 1GR-FE

OK:

Engine speed displayed on the Techstream is almost the same as the actual engine speed.

Result





C -- GO TO ENGINE CONTROL SYSTEM How to Proceed with Troubleshooting

B -- GO TO ENGINE CONTROL SYSTEM How to Proceed with Troubleshooting
A -- Continue to next step.

2. INSPECT COMBINATION METER ASSEMBLY (INPUT WAVEFORM)

(a) Check the input waveform.





(1) Remove the combination meter assembly with the connector still connected.

(2) Connect an oscilloscope to terminal C9-7 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.

HINT
As the vehicle speed increases, the cycle of the signal waveform narrows.

(5) Reinstall the combination meter assembly.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

OK -- REPLACE COMBINATION METER ASSEMBLY Removal

3. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

(a) Disconnect the C9 combination meter connector.





(b) Disconnect the E7 or E14 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





*1: for 2TR-FE

*2: for 1GR-FE

Result





(d) Reconnect the ECM connector.

(e) Reconnect the combination meter connector.

C -- REPLACE ECM Removal

B -- REPLACE ECM Removal

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR