GaryDG

I have developed a few electrical issues on my 2001 500S.

2 weeks ago I was driving during the day and my dashboard board warning light came on and a couple of the dashboard icons were flashing and the fuel level showed zero. At the same time a clicking sound came on at the rear of the car. Looking for the source of the clicking it may have been the trunk lights switching off and on, not quite sure. This sound and dashboard flashing/malfunction continued for a hour. I parked the car for a couple hours and resume the ride home. About half way home all issues disappeared.

Now I find that the license plate light stays on with the car off and fob out of the ignition - slowly draining the battery.

Any ideas?

Plutoe

All those events that you describe typically are caused by low voltage and or faulty SAM's(most new car have three) and are the cars main microprocessor voltage switchers.

The problem is that you can't fully diagnose the SAM's without factory or equal diagnostics, except when you have a license plate lamp issue you simply disconnect the assy or take the bulbs out to stop the drain---otherwise its off to the indy or dealer, plus you have the randomness issue that also complicates things which mean more diagnostic time which means more costs!

Werkzeug

Yup sounds like a rear SAM to me. I'd replace that and the IC at the same time. Save you some trouble haha.

GaryDG

That's what I needed > SAM (signal acquisition module, essentially a router on the car's electrical network).

Using that in the search function pulled up further reading and seems to confirm what you guys said - thanks!

Now concerning the IC, I presume that is an integrated circuit of some kind. Not sure where that is or what function that performs - can you elaborate?

Also, on the SAM (and I am not finished reading the posts), it seems clear that the SAM purchased must be for the car it is placed on (part number match) but what is not clear is if the SAM can be installed without any programming. Any comments there?

Thanks again!

tusabes

Sam does not need to be programmed

However you need to determine why the Sam failed . Most times its due to water damage . If you have experienced any recent rains , these cars have a problem with the AC vent ducts under the windshield that allows water to enter the passenger cabin and straight to the Sam

GaryDG

I pulled out the rear seat cushion, moved the insulation, and observed perhaps 1/8 - 3/16 of water at the bottom towards the center of the car, below the electronics but some of the wires were laying in the water.

This may also account for excessive moisture, that I couldn't determine the source of, in the trunk a couple months ago.

I will evaluate further.

wallyp

If you have not yet done so:
Open the hood (bonnet).
Look in the right rear corner (To your left - Left/Right are always from the viewpoint of a seated driver), and locate the large horizontal grille. This is the air intake for the HVAC.
Look down into the grille, using a flashlight (torch) if necessary, and see if there is any standing water at the bottom.
If there is, you must immediately clear the drain at the bottom. Water in this area will do major damage to the electrical/electronic systems in the car.

If there is water, you must remove the front and rear carpets on the right, and thoroughly dry the channels in the floor. You will also need to remove the rear seat bottom (there are release handles at each corner of the bottom) and thoroughly dry the SAM/fuse box/wiring under the seat.

ibeforreal

This is what Wally is referring to. It should be clear of leaves and other debris.

tusabes

There is water under your passenger carpet pad. It must all come out before major damage is done