GLA-531

UA. DTC 531

Condition
Diagnostic trouble code (DTC) GLA-531 is stored it the - control module registers that the courtesy lighting signal is greater than 1.5 V for 10 seconds when a door is open or when the car is unlocked using the remote control or key.

Substitute Value
None.

Possible Source
Short-circuit to supply voltage in the signal cable.
Open-circuit in signal cable.
Contact resistance in terminals.
Internal fault in control module output

Fault Symptom(s)
Courtesy lighting does not light.

Start fault-tracing with UB.


UB1. Checking Courtesy Lighting






Check that the courtesy lighting door switch is in the door position.
Ignition off.
Remove key from ignition switch.
The courtesy lighting should light.
Does the courtesy lighting light?
Yes: Go to UB6.
No: Go to UB2.


UB2. Checking Connectors

Check VGLA control module connector and courtesy light connector for contact resistance and oxidation according to WWA5 WW. Checking Wiring and Connections
Check that the courtesy lighting door switch is in the door position.
Ignition off.
Remove key from ignition switch.
The courtesy lighting should light.
Does the courtesy lighting light?
Yes: Operation done
No: Go to UB3.


UB3. Checking Cables





Ignition off.
Check cable between control module #A24 and courtesy light #5 for a short-circuit to supply voltage according to WWA4 and for open-circuits according to WWA2 WW. Checking Wiring and Connections
Were any faults found in the cable?
Yes: Fault corrected
No: Go to UB4.


UB4. Replacing Component





Ignition off.
Try a new control module according to replacing main control module.
Then continue with UB5.


UB5. Verification

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

Ignition off.
Reconnect connectors, reinstall components.
Ignition on.
Ignition off.
Remove key from ignition switch.
The courtesy lighting should light.
Does the courtesy lighting light?
Yes: Fault corrected
No: Fault not found


UB6. Intermittent Fault





Check cable between control module #A24 and courtesy light #5 for an intermittent short-circuit to supply voltage according to WWB4 and for an intermittent open-circuit according to WWB2 WW. Checking Wiring and Connections Operation done.