2003 Mercedes SL500

I've had this for some time, and let it sit for about 4 years. Getting it going again has cost a bit, but I've learned a few things

Common issues:

  • SBC pump usually needs replacing around 80 to 130k miles.
  • ABC struts can leak, pump can fail, lines can corrode, accumulators can fail. No set time - totally random.
  • Central locking pump can fail either from overwork trying to compensate for leaks (see above) or water ingress to boot.
  • Water leaks from roof and boot seals. There is a fix procedure for the boot that's very effective.
  • Water can leak through high level brake light.
  • Boot key lock prone to seizing and needs regular attention to keep it working (WD40 or similar and work the key to keep it free)
  • CAN bus connection point in sill prone to corrosion giving canbus faults on diagnostics and intermittent random issues.
  • Early cars (pre 2004) use D2B fibre optic ring for connection to CD player, phone etc. No real support for add-ons this and few options to replace head unit etc.
  • Gear selector has a small plastic interlock that can break licking the cat in park. Cheap but fiddly to replace.
  • Leaving them unused for any length of time will result in a flat consumer battery (in the boot). If not in use for over a week put a charger on it to keep it charged.
  • Fuel tank baffle comes loose and starts banging (some easy fixes with magnet)


They are not a sports car. They're a grand tourer and if you drive them as such they are a consummate cruiser. Roof up they can feel a little claustrophobic (the cabin is small for the size of the vehicle) but top down they're great. Even in the depths of winter driving with the roof down, wind deflector up, heated seats on and heater turned up is very enjoyable. Just don't expect to go too far if it snows. Wet weather grip can be a challenge too.
Cars with ABC have near zero body roll, pitch or dive and smooth out the bumps surprisingly well. They can also corner surprisingly quickly for a near 2 ton car.
I'm not going to discuss fuel economy - you don't buy these expecting frugal fuel usage!


DIY stores:
autohausAZ - Phoenix, AZ

eEuroparts - Nashville, TN

FCP Euro - Milford, CT

Pelican Parts - Harbor City, CA

Parts Geek - Doylestown, PA

RM European - Littleton, CO

ECS Tuning - Wadsworth, OH


soft close trunk lid

Mercedes Electronics

fuses and relays

Mercedes module list

fault finding & fixing & icarsoft scanner

Mercedes Hidden Menus

Mercedes parts

Mercedes HVAC

Mercedes ambient temperature sensor

Mercedes AAC Multifunction sensor

OCP Overhead Console temp sensor

Mercedes misc body


vin lookup


FSS (service light) Reset:n service a or b


  • Turn ignition to second position (but do not start car)
  • scroll with up or down button, to service indicator
  • press on odometer button for 10 seconds, then release and press 3 seconds again to confirm

on my car, it only showed service B, and reset to 10,000 milwa


  • Get in car, close the doors, and turn key to position 1
  • IMMEDIATELY hit the rest button three times (You have to do this within 3 seconds)
  • You should see the multi-function display show voltage now.
  • Scroll down using the button on the steering wheel and get to the page showing oil measurement (Can't recall exactly what it says but it will be obvious this is a service menu)
  • Turn key to position 2 (You must do this at this time)
  • You should now be able to scroll to where it will ask for oil type (I believe I only had one choice like Oil 1.0 or something to that effect.
  • Work your way thru that menu and it will ask you to hold reset for 3 seconds on the multi-function display. If you do that it will reset and you will see your next service interval.
  • The main thing is getting the voltage to come up by turning to position 1 and hitting reset 3 times in less than 3 seconds. Once you are there you will be able to intuitively work your way thru the menus. Just remember to turn it to position 2 only when you get to the service menu screen.

rear plastic trim panels



 Thread in replacing radio / head unit:


 Spiral audio bezel to fit JVC head unit







Electrical fuses/relays

Theres quite a few fuse and relay panels:

2 under the hood, one behind the seats and more

note that many systems will go offline if there is a problem, and even if the problem is cleared, often you have to reset it by pulling power, or a service tool

click here for my page on fuse/relay locations and assignments

Comprehensive site for fuses and relays:


Left engine fuses


 Left engine relays:



Right engine fuses:





mb parts online:









There are companies who can remove the finish and replace with Matt black acrylic and I have used one in the US called StickyNoMore.

cabin air filters:



sbc stop and hold


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