Geely CK Series 2007 Workshop Manual page 166

4
Make a simulation test in a way of symptom simulation
5
Inspect DTC
6
Confirm symptom
V. SYMPTOM SIMULATION
NOTES:
The most difficult conditions to handle in the fault troubleshooting are that the fault symptom dose not appear.
Under the circumstances, make sure first to make a comprehensive analysis to the fault described by the
customer, then to simulate an environment that is similar or the same with the conditions when the fault of the
customer's vehicle occurred. No matter how rich the experience of the technician is and how skillful he is, if
he make a fault troubleshooting analysis without confirm the fault symptom, it is inevitable for him to neglect
some important factors and incorrectly guess, which may cause barriers to repair. For example, if a fault
occurs only when the engine is cool or if a fault occurs only caused by a vibration from pavement and so on,
when the engine is checked in the hot or static state, it is no way to confirm. Because of vibration, high-
temperature or seeping water (Vapor) often causes some faults that are difficult to reappear. So, here are
some effective symptom simulation tests.
KEY POINTS OF SYMPTOM SIMULATION TEST:
In the symptom simulation test, no doubt it is important to confirm the fault symptom, but the fault position or
fault components must be also found out. So, before the test and the pre-inspection of connection, narrow the
range of the circuit where faults may occur according to the fault symptom. Then make a symptom simula-
tion test to see if the circuit measured is normal; the fault symptom is also verified at the same time.
1. Way of Vibration: When vibration may be the major cause of the fault.
For example:
(a) Use your hand to gently vibrate the sensor that is considered the cause of the fault, in order to check if it
is ineffective.
(b) Softly rock the connector and harness in horizontal and vertical direction.
Notes: Hard rock may cause the relay circuit open.
2. Way of Spraying Water: When rainy weather or wet environment may be the major cause of the fault.
(a) Spray water on the vehicle to check if the fault occurs.
NOTES:
Be sure not to directly spray water into the engine compartment. Spray the water on the face of the
radiator to change the temperature and humidity indirectly.
Be sure not to spray water onto electronic devices and controllers.
159