ab3344024

My 2006 SL500 start to have few problems recently. I want to know anyone have the same experience. It all started with clicking or tapping noise next to driver headrest for an hour. Then the starter battery died. I disconnected and charged the starter battery without disconnect AUX battery (not knowing the steps at that time). The starter battery is then replaced with one from MB dealer. Now, every time I start driving, a red "close trunk lid" message appear for a while then gone. Meanwhile, when the remote lock button is pressed, no parking light is flashing which I remember it did before. There is no code from COMAND menu or OBD. Any idea are they all related: something went bad causing truck close detection and remote lock without light flashing? Any idea where to check from experts?
Thanks ahead!

bobterry99

I see no common link between these two failures.

A switch in the trunk latch mechanism detects when the trunk is closed. This switch is wired to the Rear SAM located behind the passenger seat (RHD car). The problem lies with either the switch, the SAM, or the associated wiring. You can use a basic electronic multimeter to troubleshoot.

If you choose to troubleshoot yourself I would begin by checking the switch with the multimeter. This thread explains how to remove the latch mechanism and gain easy access to the switch.

If the front and rear lamps do not flash when the vehicle is locked but otherwise function, I believe this would have to be a software function. I do not know how you would correct it.

ab3344024

Thanks for your reply. Without a complete understanding and partial info, my scenario is the air pump went bad after an hour continue running (when battery low??) causing trunk lid soft close not working. Another speculation is the remote lock sequence is not competed due to trunk lid not close. Hence, no light flashing even door is locked properly. It is too late to test remote lock with trunk lid open for light flashing or not. I will do a test to remove AUX battery to see whether soft close can work few times and check light flashing. I appreciate anyone can check light flashing or not during remote lock with trunk open.

secondchance550

I just tried locking the doors with trunk open. Doors will lock but no parking lights flashing. Guess it's SL's way of telling you the trunk is open.

ab3344024

Good! Thanks for doing the experiment. It confirms that is the way SL behaves. So, there is only 1 problem instead of 2. SL computer is too smart that may scare people.

dmutch01

You described my problem exactly. Trying to see if you got yours working and whether you replaced the pump or found another fix. Thanks for any help.