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Old 12-02-2002, 07:13 PM
Senior Member
Join Date: Sep 2002
Posts: 2,486
Hi Sato, something is definitely wrong with your car! When checking the rest current draw, MB specifies checking it with the doors unlocked as well as locked. On vehicles with the COMAND system they require the NAV disc be removed as well. As far as waiting thirty minutes for all the ECU's to shut down, that may be a little mis-leading. I've done current draw tests that have lasted from less than ten minutes to well over an hour! I'll bet one of the ECU's on your cars interior data bus isn't shutting down properly. This causes the cars' electrical system to remain partially turned on, draining the battery. From the sound of your complaint(three times in 8 months) it's not a problem that always exists. Your dealer should connect an ammeter to measure the rest current draw and monitor it periodically for as long as it takes to determine the cause of your problem. I've had to monitor cars for several days before the malfunction occurred. Dead batteries caused by excessive rest current are one of the most difficult diagnosis' to make, even for a highly skilled MB tech. MB vehicles with networked ECU's make it especially challenging. Commitment to customer satisfaction and diligence are important ingredients to your dealer seeing this problem through. Good luck and let me know how it goes.
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