SL/R230: 2008 SL 55 need some help
Thread Starter
Newbie
Joined: Oct 2018
Posts: 3
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From: Wisconsin
SL55
2008 SL 55 need some help
I have a SL 55 2008 and it will not crank. Both batteries have been replaced and are fully charged. Thought it might be the ignition switch had it checked out and it is good along with the key. There are no dash lights when you turn the key on. Both a Foxwell NT510 scanner and the fault comes up on the scanner fault BNS vehicle power supply control module fault. Would this not let the vehicle crank and where can you buy one? if this is actually the problem.
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Joined: Aug 2020
Posts: 1,329
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From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
The car will start and run with a bad BNS. With two fully charged batteries, your car should wake when you unlock or when you open the door. Turning the key should turn on accessories like the radio. You probably have at least one major prefuse blown. I would start by checking the rear and front prefuses. There are a number of other things that can cause a no crank issue, but if you don't have power where is should be, you need to fix that first.
