CAN bus
1. Check the connectors and the wiring to the yellow CAN bus and the control units. 2. Check that pin A-8 (CAN_H, yellow bus) is connected to connector C481-4. 3. Check that pin A-9 (CAN_L, yellow bus) is connected to connector C481-16. 4. Check that pin A-12 (waking the ICL system) is connected to the ICL system and that it has a low pulse (1000 ms) when the alarm system is activated with a fault, for example if a door is open. 5. Check that pin B-15 (waking the visibility system) is connected to the visibility system and has a low pulse (300 ms) when the alarm system is activated, is deactivated or is triggered. 6. Check that pin B-16 (waking the GSM) is connected to the GSM module and has a low pulse (500 ms) when the alarm system is activated, is deactivated or is triggered. 7. Check that pin B-23 (waking the coordinator) is connected to the coordinator and has a high pulse (500 ms) when the alarm system is activated, is deactivated or is triggered.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
CAN messages from the alarm control unit are not confirmed by any other unit on the bus.
The fault can be caused by the following: - The yellow CAN bus has a major fault - The alarm control unit has been disconnected from the CAN bus. - The battery's main switch breaks the circuit (i.e. the battery circuit is broken).