Self-Diagnosis System - PIAGGIO 500 cc Service Manual

Fuel injection

SELF-DIAGNOSIS SYSTEM

The fuel injection control unit has a self-diagnosis function.
When an anomaly is revealed, the control unit proceeds to:
- lighting of the fuel injection indicator (only when current).
- activation of engine management controls on basic data entered in the control unit (where possible).
- memorization of the anomaly (always).
If an anomaly revealed is not always present, the indicator follows the state of the anomaly and memorization remains
active. Memorization of the event is cancelled automatically if the anomaly does not occur again for more than 16
usage cycles (warm up - usage - cooling). Disconnection of the battery does not cancel the memorization.
- Control of memorized anomalies
Connect diagnosis tester 020460Y to the vehicle sys-
tem - see page 9-17.
Selection the "ERRORS" function menu.
The pages of the tester show a list of the errors that may
be revealed during self-diagnosis.
Errors revealed through self-diagnosis are marked by
one or two reference bullets.
These are located in two rows
Row A = current anomalies (present)
Row M = memorized anomalies
Errors revealed through self-diagnosis may refer to the
following control unit system circuits or fields:
- throttle valve position signal
- ambient pressure signal
- coolant temperature signal
- air intake temperature signal
- incorrect battery tension
- Injector and related circuit
- H.V. coil and related circuit
- Stepper and related circuit
- Pump relay circuit
- Electrical fan relay circuit
- RAM Memory
9 - 38
- ROM Memory
- EEPROM
- Microprocessor
- Signals panel (revolutions - phase - unstable cycle signal)
The anomalies underlined cause the engine stopping.
In the other cases the engine works on basic data manage-
ment.