Page 44 - Foton Workshop Manual - Auman EST-M

IN - 38 Introduction - How to remove the vehicle faults

7. Remedy the faults as per fault symptom table.
The occurred fault goes beyond the inspection range of vehicle diagnostic system (the previous DTC indicates
the past possible fault or not a key part of the matter).
8. Completed.
Simulated check of fault symptom
Caution
● In case of fault remedy, it’s the most difficult that the fault symptom can’t be found. In this case, it’s
required to analyze the faults said by the client thoroughly, and then simulate the vehicle and
environment conditions in case of fault occurrence. For a repair technician, regardless of rich
experiences or proficient skills, important information of maintenance operations may be neglected
and wrong guesses may be made, if he or she fails to confirm the fault symptom while remedying the
fault.
● For example, for those faults possibly caused by cold-state running of engine or road bumps, etc
during the vehicle driving, they can’t be found out in case of hot-state running of engine or vehicle
stopping for ever. The vibration, high temperature and water leakage (moisture), etc are normal causes
for faults and difficult to reappear, so the simulated check methods of fault symptom shall be
introduced here. It’s an effective check method to simulate external factors at parking state of vehicle.

1. Key points for fault symptom simulation:
a. First be sure to confirm the fault symptom, and find out the faulty positions or parts. In order to do so, first
connect the diagnostic unit before simulating the check of fault symptom, and try to reduce the remedy range
of faulty circuit as per the fault symptom.
b. Then simulate the fault symptom to judge whether the tested circuit is damaged or normal, and confirm the
fault symptom. Check the fault symptom table of each system, and reduce the range of possible reasons for
this fault symptom.
2. Shaking method--for the fault possibly caused by
Gently shake
vibration.
a. Parts and sensor
● Shake the sensor possible to cause the fault lightly by
fingers, and check whether this fault occurs.
Caution
If it’s overexerted, it may lead to broken circuit of relay.

b. Connector

● Shake the connector lightly in horizontal or vertical
direction.
Gently shake
c.Harness
● Shake the harness lightly in horizontal or vertical
direction. The connection section of harness and connector
is main area required to look over.
Gently shake

IN-038