Page 43 - Foton Workshop Manual - Auman EST-M

Introduction - How to remove the vehicle faults IN - 37

What? Vehicle model No., system name IN

When? Date, time, frequency
Where? Road conditions DI
What conditions? Running conditions, driving conditions and climate conditions
How? Failure phenomenon EG
Confirmation of fault symptom and DTC (and data flow) check

Caution
TR
The diagnostic system has many functions.
1. The first function is diagnostic trouble code (DTC) check. The fault signals of control module circuit
can be stored in the memory of control module as codes. The repairman can check the previous DTC AX
during the operation.
2. The other function is input signal check. Check whether the signals from each switch have been FR
correctly sent to the control module. These functions can assist in quick reduction of fault remedy range
and increasing the maintenance efficiency.
ST
a. During DTC check, it’s very important to judge whether the fault indicated by this code is occurring or has

occurred, but it recovers to normal state now. In addition, in case of confirming the fault symptom, be sure to
BR
check whether the fault indicated with DTC is directly related to fault symptom. Therefore, perform DTC
check before and after confirming the fault symptom, so as to judge the current conditions of vehicle,
otherwise it will lead to unnecessary fault diagnosis and removal of normal system, added difficulty of fault BW
check or unrelated maintenance, so it’s required to check DTC as per the operation procedures.
b. How to perform the fault remedy process through DTC check, as shown in the figure below. This process
EL
indicates how to perform DTC check effectively. Finally, this process shows how to perform this fault remedy

process via DTC and fault symptom table.

1. DTC check
2. Record the shown DTC, and remove DTC.
Caution
If DTC appears in case of first DTC check, it indicates the possible faults of circuit harness or connector.
Please check relevant harness or connector. (refer to Chapter IN Preamble–How to Remove Vehicle
Faults, Circuit Check)
3. Confirmation of failures
Do the fault symptom still exist?
Yes>go to Step 4.

NO>go to Step 5.
4. Simulate the check of fault symptom. (refer to “Chapter IN Preamble-How to Remedy Vehicle Faults,
Overview”)

5. Perform DTC check again.
Does DTC appear?
Yes>remedy the fault indicated with DTC.
NO>system normal
6. Confirmation of failures

Do the fault symptom exist?
Yes>go to Step 7.
NO>system normal

IN-037