How to solve Scania truck ALM 310 siren,short circuit does not work correctly.
Preparations:
Scania SDP3 2.69.3 Truck Diagnostic Software
Error identification
Siren N9 is short-circuited to ground.
Cause
Fault in harness-to-component connectors or cable harness for siren N9.
Fault in siren N9.
Faulty ALM control unit E7.
Symptom
The siren does not work correctly.
Action
1 Disconnect siren N9.
2 Measure against ground and voltage on the pins in the nearest harness-to-component connector leading to control unit pin A11.
3 Disconnect the harness-to-component connector on the control unit.
4 Measure for short circuits throughout the cable harness.
5 If there are several harness-to-component connectors between the component and the control unit, also measure these to locate the fault.
6 If the fault is not in the cable harness or the component, it is probably an internal fault in the control unit.
