Gilera 633721 Workshop Manual page 252

Injection
15 - Check the connectors carefully. Disconnect and check the continuity between connector and pin
7-12
Electric characteristic
Connector - 7 =
Continuity
Connector - 12 =
Continuity
Fix the connectors or replace the cable harness.
16
Electric characteristic
Resistance
0
Repair or replace the injection wiring (short circuit)
17 - Check the earth insulation again.
Electric characteristic
7-23 =
infinite (>1MΩ)
YES go to 19 NO go to 18
18 - Check the sensor and control unit connectors.
Repair or replace the injection wiring
19 - Measure the alternated voltage between pins
7 and 12 with engine at start-up speed.
Electric characteristic
7-12 =
approx. 0.8 - 4.5 V eff
Revolution speed =
approx. 300-400 rpm
YES go to 20 NO go to 21
20 The sensor circuit is in conformance.
Use the parameter function to check if the engine rpm indication is present when trying to start.
If not, carefully check the ECU connection connector and replace it if necessary.
21 Check the air gap and magnetic activity of the sensor.
See the "Combustion unit and distribution" chapter.
If there is no magnetic activity replace the sensor.
N.B.
-THE SENSOR CABLE MUST BE PROPERLY INSTALLED FOR SERVICING.
-DO NOT FORCE THE CABLE.
INJEC - 252
Nexus 500 euro 3