Several times over the past year or so, my 2001 C320has had problems with my battery being drained.The information posted in these forums helped me narrow down what was causing the drain, that being the control module beneath one of my seats.The constant draw of power from the modulewascausing the battery drain and not allowing the car to start. Twice during this time the battery was drained so low that it effected the REAR SAM unit in the trunk. This causing various problems such as not being able to remotely open the trunk or doors, gas gauge constantly on empty, no turn signals or hazzards lights.[>:] I understand this is common for this to happen when the REAR SAM loosespower.
Reading thru the forums, Isaw a post describing this exact situation and followed theadvice on how to get the REAR SAM to respond again. I completely disconnected the battery from the car for about 24 hrs and when the battery was hooked back up, for whatever reason, the REAR SAM responded and everything worked again. That has worked twice in the past butthis time I cannot get it to respond.
My question is, "Is there a way to test the REARSAM unit to determine if it is defective?" Obviously I would like it topower back up as it did before butthis has not worked this time. Any suggestions are greatly appreciated.

 

It can checked using SDS (Star Diagnosis) by either the dealership or someone who has it (like me). Chances are...REAR SAM needs replacement!!!

take care,
-mar-

 

Don't believe the take it to the stealership advice and the magical mystery machine. My 2001 C320 with 36K miles on it had this very same problem. The alternator was replaced. The wipers, gas gauge, turn signals, interior lights, trunk release and remote were all inoperative following that work. It was dutifully taken in for service where the result was:

"35857 Connect SDS, performed short test, checked power supplies and grounds, performed electrical test, traced to the rear SAM, customer declined work at this time" as quoted from the invoice.

The work was declined because they quoted me 50% more cost than the two hours of labor ($125/hr) and new SAM ($400) which was checked from the stealer's own parts department. I told them the SAM could possibly need a reflashing so I knew what the problem was. I no longer believe reflashing is really necessary.

I took the car home and after thinking about the problem decided to replace the unit myself. It's easy enough. But before doing that just practice and remove it. What the heck it's "blown" anyway. The plugs and connections were carefully documented as they were removed. Not a real necessity because everything is keyed and color coded but better to be safe. After carefully plugging it all back in and checking operation of the previously failed functions everything was back in working order.

Now, the question comes up: What was the stealership actually going to do for the $1000 they wanted for the work?