LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2015 >> ML250 >> Repair and Diagnosis >> Electrical >> Motors, Switches, Relays >> Electrical System - Body - 166 Chassis - 1 Of 4 >> Basic Knowledge >> Substitute lights and emergency lights actuation, function >> Substitute lights and emergency lights actuation, function - GF82.10-P-3080GN

Substitute lights and emergency lights actuation, function - GF82.10-P-3080GN

MODEL 166 as of model year 2016 

MODEL 292 

Function requirements, general 

IMPORTANT The electronic ignition lock control unit (N73) sends the status of circuit 15 over the interior CAN (CAN B) to the SAM control unit (N10).

Substitute lamp actuation/emergency light actuation, general 

The substitute lamp actuation/emergency light actuation ensures operation of the minimum exterior lighting in the event of failure of individual system components for the vehicle's exterior lights. The substitute lamp actuation/emergency light actuation is comprised of the following subfunctions:

Function sequence, backup actuation 

The SAM control unit continuously monitors the function of the individual lamp paths or LEDs for the vehicle rear lamps. If individual lamp paths or LEDs fail, their function is simulated by actuating other lamps, where applicable, with pulse width modulation. Flashing functions have priority over steady light when this takes place.

An active automatic lamp substitution function is shown on the multifunction display (A1p13) of the instrument cluster (A1). To this end, the SAM control unit transmits corresponding requests via the interior CAN to the instrument cluster.

Actuation failure REPLACEMENT Timing device
Rear turn signal and hazard warning flasher actuation Left rear turn signal lights (E3e1) Left brake light (E3e4) No
  Right rear turn signal lights (E4e1) Right brake light (E4e4) No
Stop lamp actuation Left brake light (E3e4) Left rear fog lamp (E3/1e5) No
  Right brake light (E4e4) Right rear fog lamp (E4/1e5) No
Rear fog lights actuation Left rear fog lamp (E3/1e5) Right rear fog lamp (E4/1e5) No
  Right rear fog lamp (E4/1e5) Left rear fog lamp (E3/1e5) No

Function sequence for emergency light actuation 

The aim of the emergency lights actuation is to prevent a complete failure of the vehicle outside lights due to a processor failure or due to the failure of the interior CAN. To this end, both the SAM control unit and the trailer recognition control unit (N28/1) (with CODE 550 (Trailer hitch)) contain independent hardware that assures the emergency light function.

If the interior CAN or the SAM control unit fails, the independent hardware in the SAM control unit activates within a period of t < 3 s the standing light and low beam actuation and, depending on the status of circuit 54, the brake light actuation. If the trailer recognition control unit fails, the independent hardware in the trailer recognition control unit activates the standing lights actuation in the trailer.

Overview of exterior lights system components GF82.10-P-9998GN