Page 2564 - Foton Workshop Manual - Sauvana

62-512 DIAGNOSIS-ENGINE CONTROL SYSTEM

sprayed to check whether the failure occurs.
Note :
• Do not sprinkle water directly to the engine, but should sprinkle water on the front of the
radiator and indirectly change the temperature and humidity.
• Do not directly spill water on the electronic components.
• Care must be taken when sprinkling water to the leaking vehicle, as it may damage the
ECU.
4. Electrical connection method
(a). When the fault may be caused by excessive electrical loads, it should turn on all
electrical loads, including the heater blower, headlamp and rear window defroster to
check for malfunctions.
(b). In the simulation test of fault phenomenon, while confirming the phenomenon, it
must find out fault location or fault parts. In order to achieve this, before beginning
test and pre-connecting tester, it should narrow the possible scope of circuit failure
based on fault phenomenon, and then conduct a simulation test to judge whether
the measured circuit is normal.
(c). When encountering difficult trouble, it can make full use of troubleshooting and
diagnostic code table to conduct fault analysis and diagnosis to narrow the scope
of the fault, quickly identify the fault location and this method is very practical and
effective.
5. Diagnostic instrumentation freezing data flow method
Use the capture stream function of the diagnostic apparatus. When the data flow is
viewed at the diagnostic apparatus, the fault status is simulated in accordance with
the fault data freeze status recorded by the diagnostic apparatus.
6. Oscilloscope Method
Uses an oscilloscope to capture wave-forms, which will help you find intermittent
failures.
7. Other methods
Replacement method : before the replacement of ECU or other control module, it
should conduct fully diagnosis of other external causes, control module is a kind of
product with a high reliability and high price.
Note :
When a control unit that is likely to be damaged is inspected for replacement parts, a
possible damage control unit should be installed on the fault-free vehicle for testing and the
new control unit cannot be installed in a faulty vehicle for testing to avoid damaging control
unit.

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