Hi Scotty,
Passenger side low beam not working on my 2009 E350 mercedes. I replaced the bulb but it still is not working. My Autel tester says that there is an open circuit. As far as I can tell there is no fuse that only affects the passenger side low beam and the driver side is working fine. Any idea best way to trouble shoot this?
Thanks
Daniel
First record and then clear any codes because with a circuit code present the control unit may not allow power to that low beam circuit to protect itself.
Low beam actuation
Function requirements
^ Circuit 30
Function
The driver-side SAM control unit reads in the position of the rotary light switch, forwards the request over CAN-B to the front passenger-side SAM control unit and actuates the left low beam.
The front passenger-side SAM control unit actuates the right low beam.
Since there's an Open circuit code you may want to backpin the connector at the Low Beam Headlight and make sure there's Power on the White/yellow wire and Ground on the Brown wire.
If there's no Power on the White/yellow wire go to the Passenger Side SAM Control Unit (N10/11) and backpin that White/yellow wire there to see if the unit is outputting voltage on Pin 2.
That's all I got. German wiring diagrams give me a headache.
Thanks. The wires are pretty hard to access. Any tricks for that? also what is backpin?
No tricks. You need to access those wiring connectors to test for Power and Ground
.
Back probing (backpinning) is simply using a probe or a pin at the back of the wiring connector while the connector is still plugged in to test for Power or Ground
Thanks, D
Use a wiring diagram to aid in tracing out the circuit to find the fault.
