Page 91 - Foton Workshop Manual - Auman EST-M

Diagnosis - Diagnosis-fault diagnosis of electronic and electrical parts DI - 37

Fault of accelerator pedal IN
131- The circuit voltage of accelerator pedal or joy stick position sensor 1 is higher than the normal
value or short to the high voltage power supply DI

132- The circuit voltage of accelerator pedal or joy stick position sensor 1 is lower than the normal
value or short to the low voltage power supply EG
1239- The circuit voltage of accelerator pedal or joy stick position sensor 2 is higher than the normal
value or short to the high voltage power supply
TR
1241- The circuit voltage of accelerator pedal or joy stick position sensor 2 is lower than the normal
value or short to the low voltage power supply
AX
1242-accelerator pedal or control lever position sensors 1 and 2-unstable, intermittent or incorrect data

Overview
FR
The potentiometer accelerator pedal position sensor operates as per the principles of bleeder circuit, and ECM

feeds 5V voltage to the sensor circuit. The electronic accelerator pedal is connected to electric brush of slide
ST
rheostat inside the sensor through a rotation shaft. When the position of accelerator pedal position sensor is
changed, the voltage between the electric brush and ground terminal will be changed, ECM will convert this
voltage into a positional signal of accelerator pedal, and ECM will monitor both slide rheostats inside the BR
accelerator pedal to ensure the reliability of output signal.
Failure protection BW

1. When any fault occurs to the accelerator pedal position sensor, the engine control unit will start the failure
protection mode in time to keep the engine running as much as possible, but it will make its operating
EL
performance reduced in different levels.

2. If either of both accelerator pedal position sensors is defective, the engine ECM will store the faults into the

fault memory and activates the fault indicator lamp of combination instruments; it will start the idling

identification mode, and the engine ECM will identify the idling request through the brake lamp switch; it will
stop the cruise control system, etc.
3. If both accelerator pedal position sensors are defective, the engine ECM will store the faults into the fault
memory and activates the fault indicator lamp of combination instruments; it won’t response to any action of
accelerator pedal, but it will make the engine keep running at a certain speed.

DI-037