2.2.7 Diagnostic Information and Procedures
2.2.7.1 Diagnostic Description
Before diagnose the control system, please refer to
and
. Understand and become
familiar with control system working principle and then start systematic diagnosis, so that in the event of faults it will help determine
the correct Diagnostic Steps, more importantly, it will also help to determine whether the customer described situation is normal or
not.
Any control system fault diagnosis should start with "Control System Check" as a starting point. "Control System Check" will guide
the service personnel to take the next logical step to diagnose the fault. Understand and the correct use of diagnostic flow charts
can reduce diagnostic time and avoid misjudging a component.
2.2.7.2 Control System Check
Before the control system check, please do following preliminary checks:
1. Check the battery terminal voltage to ensure an adequate power supply and a stable voltage.
2. Check the battery cables, clean and tighten.
3. Check the easy to access system components whether there are obvious damages that may cause the symptoms, such as
vacuum tube damage and the reliability of wiring harness connectors connection.
4. Check control module and battery ground points whether there are copper oxidizing or signs of loosening.
5. Check control system whether it is likely to affect the normal system operation after the installation of aftermarket equipments.
Diagnostic Steps:
Step 1
Verify customer described faults.
Next
Step 2
Connect a scan tool.
(a)
Install the scan tool.
(b)
Turn on the scan tool.
Is the scan tool connected?
No
Yes
Step 3
Start communication between the scan tool and the engine control module.
(a)
Turn the ignition switch to "ON", but do not Start the engine.
(b)
Try to establish communication between the scan tool and
engine control module (ECM) .
Can the scan tool communicate with engine control module?
No
Yes
Step 4
Start the engine and run at idle speed. Can the engine start?
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Control System JL4G18-D
Engine
EC718/EC718RV EC715/EC715RV 10/2009
Summary of Contents for EC715 2009
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