Description - Sym Citycom.300i Service Manual

Fuel Injection System Components Description
ECU (Engine Control Unit)
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Function Description:
Powered by DC 8~16V, and has 36-pin socket on the unit.
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The hardware component consists of a 16-bit microcomputer that is its
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control center. It contains the functional circuit interface of engine
condition sensing and the driving actuator for the fuel injector, fuel
pump, as well as ignition coil.
Its major software is a monitor strategy operation program that
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includes controlling strategy and self-diagnosis programs.
Testing Procedures:
1. Connect the diagnostic scanner to the diagnostic coupler on the
vehicle.
2. Key-on but not to start engine, confirm ECU and the diagnostic
scanner can be connected or not.
3. Diagnostic scanner will automatically display Version "certification" of
the screen.
4. Confirm the application model, version is correct or not.
5. Check if the fault codes exist.
6. Remove the fault codes.
7. Start engine and check the parameters shown on the diagnostic
scanner.
Detection Judgement:
Fault codes can be read and cleaned, and the fault codes will not
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appear again after re-start.
Treatment of abnormal phenomena:
1. Can not connect→ First check whether the cartridge is correct and
ECU is normal or not.
2. Unable to start→ ECU or relevant parts abnormal. Re-confirm after the
replacement of abnormal parts.
3. Fault codes appear→ ECU or relevant parts abnormal. Troubleshoot
4. Fuel Injection System
and re-confirm.
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