Checking the Brightness Switch

Checking the BRIGHTNESS switch

Checking the fuses and the power supply
Check that the fuses for the rear display screen and M2D control module are intact and that there is power supply to the fusebox.
The voltage must be approximately 12 V.
The fuses are positioned under the rear center armrest.
Check that the radio is switched on.
Set the mode to TELEVISION using the SOURCE button on the radio unit.

Checking the M2D control module and the BRIGHTNESS switch
Check the voltage between terminals #N1-10 and #N1-13, when the BRIGHTNESS switch is pressed in. See position 3 for the location of the connector.
The voltage must be approximately 12 V.
Check the voltage between terminals #N1-10 and #N1-13, when the BRIGHTNESS switch isnotpressed in. See position 3 for the location of the connector.
The voltage must be approximately 0 V.
Check the cable between the M2D control module terminal #N1-10 and the BRIGHTNESS switch terminal pin 4. Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the voltage between terminal 3 and ground on the BRIGHTNESS switch.
The voltage must be approximately 12 V.
Remedy as necessary.

Other information:
- For information about signals and connectors, see Signal specification, RTI (road traffic information) Executive Signal Specification, RTI (Road Traffic Information) Executive
- To access and replace the switch, see Replacing switches Replacing Switches
- To access or replace the M2D control module, see Road traffic information module (RTI), replacing Service and Repair.

Hint: The above illustration shows the location of the M2D control module on the RTI unit.

- To access or replace the fuses, see Location of fuses in the rear center console Executive Location of Fuses in the Rear Center Console Executive
- To fault-trace wiring and terminals see Checking wiring and terminals Checking Wiring And Terminals









Was a fault detected?

Yes - FAULT FOUND

No - No Fault Found

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