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 (Component Tests and General Diagnostics).

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTE: If the vehicle speed is outside the allowable range when tested, perform the following procedure (Component Tests and General Diagnostics).

PROCEDURE

1. SYSTEM CHECK
Result:

B -- INSPECT COMBINATION METER ASSEMBLY
A -- Continue to next step.
2. READ VALUE OF TECHSTREAM (VEHICLE SPEED SIGNAL)
(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 ABS/TRAC/VSC: Chassis / ABS/VSC/TRAC / Data List.
(g) Check values by referring to the table below.

ABS/VSC/TRAC:

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

(1) Remove the combination meter with connectors still connected.
(2) Connect the oscilloscope to terminal C11-18 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.

Result:

D -- INSPECT SPEEDOMETER SENSOR
C -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ABS & TRACTION ACTUATOR ASSEMBLY)
B -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE ACTUATOR ASSEMBLY)
A -- REPLACE COMBINATION METER ASSEMBLY
4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the C11 and S1 connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT BRAKE ACTUATOR ASSEMBLY

(a) Disconnect the S1 connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPLACE COMBINATION METER ASSEMBLY
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY
6. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ABS & TRACTION ACTUATOR ASSEMBLY)

(a) Disconnect the C11 and S1 connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. INSPECT ABS & TRACTION ACTUATOR ASSEMBLY

(a) Disconnect the S1 connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- REPLACE ABS & TRACTION ACTUATOR ASSEMBLY
8. INSPECT SPEEDOMETER SENSOR
(a) Check voltage.

(1) Shift the shift lever to neutral.
(2) Jack up either of the front wheel.
(3) Turn the ignition switch to the ON position.

(4) Measure voltage between terminals 2 and 3 of speed sensor when the front wheel is turning slowly.
Standard voltage:
Voltage is generated intermittently.
NG -- REPLACE SPEEDOMETER SENSOR
OK -- REPLACE HARNESS OR CONNECTOR (SPEEDOMETER SENSOR CIRCUIT)