Page 107 - Foton Workshop Manual - Auman EST-M

Diagnosis - Diagnosis-fault diagnosis of electronic and electrical parts DI - 53

Speed sensor failure IN
241-based on the speed RPM of wheel-missing of unstable data, intermittent or incorrect ECM speed
signals. DI
Overview

The vehicle speed sensor is a Hall-effect sensor that works with the signal wheel on the output shaft of the EG
transmission. The ECM receives the digital voltage signal from the sensor to determine the current speed of

the vehicle. The speed sensor shall be installed in the trail of transmission.
TR
Check on vehicle

1. Start the engine to make it reach its normal operating temperature.
AX
2. Ignition switch: LOCK.

3. Connect the diagnostic unit to the fault diagnostic interface (16 pin) under the instrument panel.
FR
4. Ignition switch: ON.

5. Start the diagnostic unit, make the vehicle driving, and read the data flow of diagnostic unit: vehicle speed.
ST
6. Vehicle speed: its displayed value is the same as actual speed of vehicle.

7. If its displayed value is different from its actual speed, check the speed sensor, harness, connector and
BR
engine ECM.

8. Lift up the vehicle.
BW
9. Ignition switch: ON. Don’t start the engine. Check the
following points:
EL
a. Turn the digital multimeter to DC Voltage gear. Its both

probes can measure the voltage between Pins 1 and 2 of

sensor from the back of speed sensor, which shall have 24V
reference voltage. If abnormal, check the harness.
b. Start the engine to run at gear, and adopt an oscilloscope
to check whether the waveform of sensor #2 terminal output

signal is normal. If abnormal, check the harness and sensor.

DI-053