Page 697 - Workshop Manual - Tunland (2017)

DIAGNOSTICS - ENGINE CONTROL SYSTEM 04-11

failure phenomena before the test is conducted and the tester is connected in advance. 04
Then phenomenon simulation test may be conducted so as to determine whether or
not the tested circuits are normal.

In case of failures that are hard to be handled, the list of troubleshooting and diagnosis
codes may be utilized to conduct failure analysis/diagnosis so as to reduce the range
of failure and find out the failure location quickly. The said method is considered as
fairly practical and effective.
5 . Diagnostic apparatus data-stream freezing method.
Use the data stream capturing function of diagnostic apparatus. Simulate the failure
conditions as per the frozen failure data recorded by the diagnostic apparatus when
people read the data stream displayed by the diagnostic apparatus.

6 . Oscilloscope method.
Oscilloscope may be used to capture the waveforms such that the intermittent failures
may be found out quickly.
7 . Other methods.

Part replacement method.To replace ECM or other control modules, conduct adequate
diagnosis of other external causes since ECM is an expensive product with high
reliability.

WARNING
To conduct part-replacement check of a control unit that might be damaged, the said
control unit shall be mounted onto a failure-free vehicle and subjected to tests.The
new control unit must not be mounted onto a faulty vehicle and subjected to relevant
tests so as not to damage the control unit.