Page 160 - Foton Workshop Manual - Auman EST-M

DI - 106 Diagnosis - Diagnosis-fault diagnosis of electronic and electrical parts

Diagnosis system
1. System overview

All the monitored faults will be stored in internal fault memory area of ECU. The stored faults can be read out
via flashing codes or fault diagnostic interface.
ABS system faults can be divided into actual fault and stored fault.
Actual fault: e.g. sensor broken/short circuit, broken/short circuit of solenoid valve in current ABS system, etc
Stored fault: faults not removed from ECU, occurred but disappeared in ECU after the repair, e.g. sensor or
solenoid valve conductor with electric connector, etc.
ABS system also has non-system faults (failure of ABS, but extinguishing of fault indicator lamp): wrong
connection of sensor/solenoid valve conductors, faults of solenoid valve air lines caused by contamination and
seizure, etc.
2. Failure lamp

a. When the system has no faults.
● After turning the ignition switch to “ON”, the system will
perform self-test, and the fault lamp will be on for 2s before
extinguishing.
● After turning the ignition switch to “LOCK”, the fault
lamp will go out immediately.
b. When any fault occurs to the system
● After turning the ignition switch to ON, the fault indicator
lamp will be always on.
● After removing the faults of ABS system, the fault
lamp will go out at over 7km/h speed.
3. Fault diagnosis
a. Diagnosis of diagnostic unit
● Connect the diagnostic unit to diagnostic interface.
● Turn the ignition switch to “ON”, and start the diagnostic unit to enter into “ABS” system.
● Read and clear the fault codes, and read the data flow of ECU/sensor/actuator as per the hints of diagnostic
interface.
b. Diagnosis of flashing codes
● Pull out the ground wire (or ground switch) in the
Combination direction of ECU to ABS indicator lamp.
instrument
● Ground the ground wire or switch for 1s, and then
disconnect it.
Flashing ● ABS fault indicator lamp will flash after 1.5s, and
code determine the flashing codes as per the flashing frequency.
diagnostic
switch One flashing code represents one fault. One flashing code is
divided into two groups, the first group can flash 1 to 8
times, and the second group can flash 1 to 6 times. The
interval between the flashing codes is 1.5s. The interval
between the groups is 4s.
● Determine the current fault as per the list of flashing
codes.
● If it’s a current fault, the lamp will display a type of code
repeatedly. If it’s a stored fault, the lamp will go out after
displaying different fault codes.

DI-106