GLA-451

LA. DTC 451

Condition
Diagnostic trouble code (DTC) GLA-451 is stored if the control module registers that the movement sensor self-test pulse is missing when the alarm is powered up, armed or disarmed.

Substitute value
None.

Possible Source
Short-circuit to ground or supply voltage in communication cable.
Open-circuit in communication cable.
Interference affecting communication cable.
Fault in movement sensor power supply.
Open-circuit in movement sensor ground lead.
Internal fault in movement sensor.

Fault Symptom(s)
The indicator LED flashes for 15 seconds when the ignition is switched on.
The movement sensor will not react to movement in the passenger compartment.

Start fault-tracing with LB.


LB1. Erasing Diagnostic Trouble Codes (DTCs)





Ignition on.
Erase diagnostic trouble codes (DTCs).
Then continue with LB2.

LB2. Reading Off Diagnostic Trouble Codes (DTCs)

Remove key from ignition switch.
Ensure that all doors, the hood, trunk lid/tailgate are closed.
Lock the car with the remote control.
Wait approximately 10 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Does diagnostic trouble code (DTC) GLA-451 recur?
Yes: Go to LB9.
No: Go to LB3.


LB3. Checking Connectors






Ignition off
Expose VGLA control module according to replacing main control module.
Expose movement sensor according to replacing movement sensor.
Check movement sensor and VGLA control module connectors for contact resistance and oxidation according to WWA5 WW. Checking Wiring and Connections


Ignition on.
Erase diagnostic trouble codes (DTCs).
Then continue with LB4.

LB4. Reading Off Diagnostic Trouble Codes (DTCs)





Remove key from ignition switch.
Ensure that all doors, the hood, trunk lid/tailgate are closed.
Lock the car with the remote control.
Wait approximately 10 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Does diagnostic trouble code (DTC) GLA-541 recur?
Yes: Go to LB5.
No: Fault corrected


LB5. Checking Cables






Ignition off
Check cable between control module #A25 and movement sensor #2 for a short-circuit to ground according to WWA3, short-circuit to supply voltage according to WWA4, and for an open-circuit according to WWA2. Check cable between control module #B17 and movement sensor #3 for a short-circuit to ground according to WWA3, short-circuit to supply voltage according to WWA4, and for an open-circuit according to WWA. Check cable between movement sensor #5 and ground for an open-circuit according to WWA2 WW. Checking Wiring and Connections

Remedy as necessary.
Were any faults found in the cables?
No: Go to LB6.
Yes: Go to LB7.


LB6. Replacing Component

Try a new movement sensor according to service and repair.
Then continue with LB7.


LB7. Erasing Diagnostic Trouble Codes (DTCs)





Ignition on.
Erase diagnostic trouble codes (DTCs).
Then continue with LB8.

LB8. Verification





Hint: After carrying out the repair, check that the fault has been remedied as follows:

Ignition off
Reconnect connectors, reinstall components.
Remove the key.
Ensure that all doors, the hood, trunk lid/tailgate are closed -
Lock the car with the remote control.
Wait approximately 10 seconds.
Unlock the car with the remote control.
Ignition on.
Read off diagnostic trouble codes (DTCs).
Does diagnostic trouble code (DTC) GLA-541 recur?
Yes: Fault not found
No: Fault corrected


LB9. Intermittent Fault






Check cable between control module #A25 and movement sensor connector #2 for an intermittent short- circuit to ground according to WWA3, an intermittent short-circuit to supply voltage according to WWB4 and an intermittent open-circuit according to WWS2. Check cable between fuse 15 and ultrasonic sensor connector #6 for an intermittent open-circuit according to WWB2. Check cable between ultrasonic sensor #7 and ground for an intermittent open-circuit according to WWB2 WW. Checking Wiring and Connections Operation done