181

3. TACHOMETER MALFUNCTION

CIRCUIT DIAGRAM

Inspection procedure

(a) Inspect the combination meter assembly revolution input signal

1

Remove the combination meter assembly and retain the connection of connectors.

2

Connect the oscilloscope to the terminal B11 and

ground.

3

Start the engine

4

Inspect the signal wave form

Standard:

Show the correct wave form

Result and solution:

Normal Inspect and replace the combination

meter assembly

Abnormal Inspect the engine ECU revolution out-

put signal

Engine ECU

Combined Meter Assembly

Engine Revolution Signal

182

(b) Inspect the engine ECU revolution output signal

1

Remove the engine ECU and retain the connection of connectors.

2

Connect the oscilloscope to the terminal 54 and ground.

3

Start the engine

4

Inspect the signal wave form

Standard:

Show the correct wave form

Result and solution:

Normal Repair or replace the harness or

connector

Abnormal Inspect the engine control system

183

4. WATER TEMPERATURE GAUGE MALFUNCTION

CIRCUIT DIAGRAM

(a) Get the value of water temperature with the diagnosis tester

1

Connect the diagnosis tester to the diagnosis interface

2

Turn the ignition switch to ON

3

Read the value of engine water temperature displayed on the diagnosis tester

 Standard: The same with the actual engine coolant temperature.

Result and solution:

If it is normal, the water temperature gauge has no malfunction

If abnormal, Inspect the combination meter assembly

(b) Inspect the combination meter assembly

1

Inspect resistance

Remove the combination meter assembly and disconnect connectors

Inspect continuity between terminals

Water Temperature Sensor

Combined Meter Assembly

Water 
Temperature 
Signal

184

Standard:

Result and solution:

Normal Replace the combination meter assembly

If abnormal inspect the water temperature sensor

2

Inspect the water temperature sensor

Remove the water temperature sensor and put it into the constant temperature cabinet.

Adjust the temperature in the constant temperature cabinet and measure the resistance of the

water temperature sensor.

Standard:

Result and solution:

Normal Repair or replace the harness and connector

If abnormal replace the water temperature sensor

Tester connection

Condition

Standard condition

C(60℃ )

164.5±5Ω

1/2C(90℃)

56±3Ω

H(115℃)

28.7±2Ω

B5 - ground

Condition

Standard condition

C(60℃

)

164.5±5Ω

1/2C(90℃

)

56±3Ω

H(115℃

)

28.7±2Ω