Communication Fault
Communication fault
Checking for permanent or intermittent faults
Open the driver's door window. Lock the car using the remote control.
Wait 25 seconds until the vehicle has been alarmed. Trigger the alarm by inserting a hand through the window and unlocking the door from the inside using the internal door handle.
Note! On vehicles with deadlocks, these must be deactivated first. Press the button for the reduced locking position to activate deadlocks.
The function can be engaged in ignition position I and 0. It can also be engaged after the ignition has been switched off, for up to one minute after the ignition key has been removed from the ignition switch. The switch has an integrated light emitting diode for indicating that the function has been activated. A message also appears in the display in the Driver information module (DIM),however, not when the key has been removed. The switches may be positioned differently than shown in the image, depending on the vehicle's configuration and equipment.
Is the siren triggered?
Yes - Intermittent fault
No - Checking the connectors
-------------------------------------------------
Checking the connectors
- Check the connectors for the siren, upper electronic control module and cable harness. Check for contact resistance and oxidation.
In particular, check for any damage
- Reinstall the components, reconnect the connectors etc.
Open the driver's door window. Lock the car using the remote control.
Wait 25 seconds until the vehicle has been alarmed. Trigger the alarm by inserting a hand through the window and unlocking the door from the inside using the internal door handle.
Note! On vehicles with deadlocks, these must be deactivated first. Press the button for the reduced locking position to activate deadlocks.
The function can be engaged in ignition position I and 0. It can also be engaged after the ignition has been switched off, for up to one minute after the ignition key has been removed from the ignition switch. The switch has an integrated light emitting diode for indicating that the function has been activated. A message also appears in the display in the Driver information module (DIM),however, not when the key has been removed. The switches may be positioned differently than shown in the image, depending on the vehicle's configuration and equipment.
Other information:
- To access the siren connector, see Siren, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals.
Is the siren triggered?
Yes - Verification
No - Checking for open-circuits and short-circuits
-------------------------------------------------
Checking for open-circuits and short-circuits
Check that the fuses in the fusebox in the passenger compartment are intact.
Check the cable between control module terminal #21 and siren terminal #2. Check for a short-circuit to ground. Check for an open-circuit. Check for a short-circuit to supply voltage.
Check the wiring from the fuse in the passenger compartment to siren connector terminal #1. Check for an open-circuit. Check for a short-circuit to ground.
Other information:
- For further information about signals and other values, see Signal specification Signal Specification, Upper Electronic Module (UEM)
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access the siren connector, see Siren, replacing Service and Repair
- For further information about the fuses and relays, see the Wiring Diagram
- Checking wiring and terminals Checking Wiring And Terminals.
Remedy as necessary.
Was a fault detected?
Yes - Verification
No - Replacing the component
-------------------------------------------------
Replacing the component
Replace the siren. See Siren, replacing Service and Repair.
The siren must be configured after replacement. Click on the VCT2000 symbol for configuration.
Continue - Verification
-------------------------------------------------
Intermittent fault
Check the connectors for the upper electronic module (UEM) and the siren. Check for contact resistance and oxidation. Check for loose connections.
Check that the fuses in the fusebox in the passenger compartment are intact.
Check the cable between control module terminal #21 and siren terminal #2. Check for an intermittent short-circuit to ground. Check for an intermittent open-circuit. Check for an intermittent short-circuit to supply voltage.
Check the cable between ground terminal 31/94 and siren connector terminal #3. Check for an intermittent open-circuit.
Check the cable between the fuse in the fusebox in the passenger compartment and siren connector terminal #1. Check for an intermittent open-circuit. Check for an intermittent short-circuit to ground.
Try replacing the siren if no fault is found.
Other information:
- For further information about signals and other values, see Signal specification Signal Specification, Upper Electronic Module (UEM)
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access the siren connector and to replace the siren, see Siren, replacing Service and Repair
- For further information about the fuses and relays, see the Wiring Diagram
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault-tracing information
-------------------------------------------------
Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reinstall the connectors, components etc.
Open the driver's door window. Lock the car using the remote control.
Wait 25 seconds until the alarm is active. Trigger the alarm by reaching into the car and unlocking the door from the inside using the internal door handle.
Is the function OK?
Yes - Verification completed
No - Fault-tracing information
-------------------------------------------------
Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit Fault-Tracing
No - Attempt New Test
------------------------
Attempt New Test - Checking for permanent or intermittent faults
-------------------------------------------------
Fault-tracing information
Information
Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).
Do you want to view the information again?
Yes - Attempt New Test
No - Exit fault-tracing
------------------------
Attempt New Test - Checking for permanent or intermittent faults
-------------------------------------------------