Alex L

Hello,

I'm going around in circles at the moment and need some help.

I can see that the backup lamps are fed power from the rear SAM.

Q: How does the rear SAM get the signal to switch on the backup lamps?

So far I've checked the wiring diagrams for both, TCU, body control module (aka passenger SAM) and Electronic Gear Selector module - nothing too obvious here.

I need this as I've put a manual gearbox in the car and need to wire up the rear lights and rear parking sensors upon reverse.

I can bypass the SAM, give the lamps ingition live and use the gearbox switch as a circuit breaker but before I do, there's surely got to be another way for the backup lights to turn on?

Any ideas are welcome.

Thanks.

Alex L

To answer my own question, that might be the central gateway module. I'm going to dig a bit deeper tomorrow.

bbirdwell

N15/5 Electronic Selector Module via CAN C bus to N93 Central Gateway then via CAN B bus to N10/2 Rear SAM. CAN C bus is on connector X30/5, the CAN B bus in question is on connector X30/7.

Alex L

Thank you. Got it figured out yesterday and made the reversing lights working. Had to slightly recode both the CGW module and the passenger SAM. Lights and PTS come up now as they should on standard wiring.

bbirdwell

If you would post how you did the above it would be valuable info to place in the "Star Diagnostic DIY" in the stickies in the W211 AMG sub-forum.