Service lever positions:
- 1 - Normal operating position;
- 2 - The position in which the diagnostics are performed.
When the ignition key is turned to position 2, the yellow indicator light on the speedometer and the yellow 4 MATIC light on the instrument cluster come on.
The yellow indicator light comes on when driving if the differential lock is additionally connected to the front wheel drive. The differential locks as long as the vehicle is moving on a slippery surface.
The activation of the 4 MATIC all-wheel drive depends on the road conditions.
[Original source of information: MercedesMan]
If the 4 MATIC indicator lamp lights up with the engine running or together with the yellow indicator lamp on the speedometer, there is a fault in the all-wheel drive system. In this case, move the service lever in the engine compartment to the right as far as it will go to position 2. The vehicle will then be driven only by the rear wheels.
If there is a fault in the all-wheel drive system, please contact a Mercedes-Benz service station.
When diagnosing the all-wheel drive, the service lever in the engine compartment must be set to position 2. In this case, the all-wheel drive indicator light comes on and immediately goes out.
The time for diagnosing a four-wheel drive should not exceed 15 minutes.