Speedometer Malfunction

METER: METER / GAUGE SYSTEM: Speedometer Malfunction
- Speedometer Malfunction

DESCRIPTION

Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart On-Vehicle inspection.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
If the vehicle speed is outside the allowable range when tested, perform the following procedure On-Vehicle inspection.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to the ON position.

(c) Turn the tester ON.

(d) Enter the following menus: Body Electrical / Main Body / Active Test.

(e) Check the operation by referring to the values in the table below.

Combination Meter:





*1: for U.S.A.

*2: Except for U.S.A.

OK:

Needle indication is within the allowable range.

NG -- REPLACE COMBINATION METER ASSEMBLY
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to the ON position.

(c) Turn the tester ON.

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

(e) Check the values by referring to the values in the table below.

Combination Meter:





OK:

Vehicle speed displayed on the tester is almost the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

NG -- READ VALUE USING TECHSTREAM

OK -- REPLACE COMBINATION METER ASSEMBLY

3. READ VALUE USING TECHSTREAM

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to the ON position.

(c) Turn the tester ON.

(d) Enter the following menus: Chassis / ABS/TRAC/VSC / Data List.

(e) Check the values by referring to the values in the table below.

ABS/TRAC/VSC:





OK:

Vehicle speed displayed on the tester is almost the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

NG -- GO TO BRAKE CONTROL SYSTEM
OK -- Continue to next step.

4. INSPECT COMBINATION METER ASSEMBLY

(a) Disconnect the S3 connector.





(b) Measure the voltage according to the value(s) in the table below.

Standard voltage:





*1: without VSC

*2: with VSC

Result:





C -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ABS & TRACTION ACTUATOR ASSEMBLY)

B -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE ACTUATOR ASSEMBLY)
A -- Continue to next step.

5. INSPECT COMBINATION METER ASSEMBLY

(a) Check the input signal waveform.





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

(2) Connect the oscilloscope to terminal C10-35 (SI) and body ground.

(3) Turn the wheel slowly.

(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.

Result:





C -- REPLACE ABS & TRACTION ACTUATOR ASSEMBLY

B -- REPLACE BRAKE ACTUATOR ASSEMBLY

A -- REPLACE COMBINATION METER ASSEMBLY

6. CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the S3 and C10 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 COMBINATION METER ASSEMBLY

7. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ABS & TRACTION ACTUATOR ASSEMBLY)

(a) Disconnect the S3 and C10 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 COMBINATION METER ASSEMBLY