Hi there,

I own an SL600 V12 (brand new igntion coils + spark plugs which are 10 months old).

With the weather being very bitter & cold this winter. I havent used my car properly since Christmas and have been leaving it on the driveway without starting it for 2-3 weeks.

Last month I started the car for the first time in a month & have got several messages: The first one was Brake Fail - Do not Drive! following by continious "Beeps". After driving it for 5 mins the "beep beep beep" noise disappears but nothing was wrong with my brakes.

Periodically I would restart my car after 5-7 days of not using it. I would get the same message & I would resolve this by driving it to charge up the battery. However when I restarted the car a day later - "Brake Fail - Do not Drive!" disappears. However this error message is replaced by a red Battery Light (Visit Workshop). I have been ignoring this error over few weeks until I promised myself battery that today I would charge all batteries before something worse happens.

However today was a day too late. As I was driving home I started to lose power & at slow traffic the accelerator failed to engage! I had to restart the car for it to re-accelerate. However when inreasing speed the power loss begin. Then my worst nightmare the dreaded "Check Engine light" appeared along with the Red Battery (Visit Workshop).

I am very worried that the ignotion coils might be misfiring again? However I only had the left & right bank (brand new) igniotion coils (plus 48 new spark plugs) installed about 10 months ago?! Surely the ignition coil or spark plugs havent died already have they?

Could my problem be a combination of not using my car regularly. When I had regularly used my car before x-mas I never had a single problem at all!

Could it be an alternator issue? Will a dieing alternator be responsible for Engine Light logo to light up, and to cause the igniton coils to misfire?

I have a 2007 SL600 that exhibited the same initial problems you describe. I had accidentally left the car in accessory mode with the fan running on high for about 3 hours. When I got back to the car, even the "keyless-go" and trunk release would not work. After I started the car manually using the key fob, the warnings and red display eventually went back to normal except for non essential accessories being unavailable. When I got home, I put the car on a C-TEK trickle charger over-night and it was fine the next morning. I have had no problems since then. I am not sure why your check engine light is on and why your car died in traffic. Perhaps the low battery affected one of the computer modules and the module needs to be reset. hopefully you will get your car back to normal soon. TwinCam

Ok,

I have charged the rear battery overnight. First thing I noticed all my interior electrics + roof & central locking now works again. However I still had 3 malfunctions. (1. Check Coolant) message appeared (2. Red battery (visit workshop) still appeared. (3. The check light was still yellow).

I took the car onto the road & noticed I wasnt losing any power. I parked up & then began to charge the engine battery. After 10 mins of charging the Charger indicated a green light (fully charged). So after unplugging leads, I restarted engine.

The check engine lights disappear!! This means my new ignition coils are still working. My only errors are now "Check Coolant" and the red battery - visit workshop - appearing.

Does this mean my rear battery is knackered & requires replacing?

Those same warning lights appeared on my car while the battery was very low and went off after the battery was full charged. The good news is any reputable shop can check the battery and see if it can hold a charge. It is easy to check the coolant and top it off if it is low. The battery in the SL lasts about 4-5 years on average and is expensive to replace due to its unusual size. I replaced mine 5 months ago after it started to run down after not driving the car for a few days. Everything works fine now. TwinCam

I've had the Red Battery (Visit Workshop) happen two times.

Once when I was changing pads and disconnected both batteries. The connection was loose on the starter battery and tripped the error. I drove with it for a couple of days and it just wouldn't go away. I unplugged BOTH batteries for about an hour and it finally reset.

The next time was when the dealership replaced the battery terminal on the starter battery. When I picked up the car the red battery light was on. They took it back real quick and plugged it in to a star machine to reset it.

I am pretty sure the Red Battery error has to do with the starter/engine bay battery.

Reading the post on SL600, I've 1993 MB sl600 - do I have two batteries too? where is the ohter one located?.. I have problems with rear battery drains overnight.....has anyone experience this, can you share?