Gilera 633721 Workshop Manual page 203

Nexus 500 euro 3
8 - Fix any wiring short circuits and replace the
fuse.
YES go to 1 NO go to 9
9 - Check any short circuit on decoder or control
unit and replace, if necessary.
YES go to 1
10 - Place the special tool between control unit and
power supply system. Disconnect the main de-
coder connector and check the following condi-
tions:
Terminal no. 3= battery positive
Terminal no. 4= battery negative
YES go to 11 NO go to 13
Specific tooling
020481Y Control unit interface wiring
11 - Decoder with proper base power supply.
Use the special tool to check the control unit power
supply:
Pin 17 = battery positive
Pin 23 = battery negative
YES go to 12 NO go to 13
12 - Control unit with proper base power supply.
13 - If the battery negative is not present, check
continuity between Pin 23 of the special tool and
earth.
Detect the presence of the battery positive on Pin
17 of the special tool and on pin 3 of the decoder
connector.
YES go to 12 NO go to 14
YES go to 11
14 - Fix the cable harness.
Key-switch power supply circuit check
A failure of the constant power supply disables both ignition and injection functions. In case of power
supply faults, the diagnostic tester gives the information "NO REPLY FROM THE CONTROL UNIT".
Injection
INJEC - 203