Christiaan Soerjo

New Member
Mar 6, 2018
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Your Mercedes
2001 CL500 -W215
Dear All!

My name is Christiaan and I live in The Netherlands, a mile from the John Frost bridge, known for the Battle for Arnhem... (WWII, Operation Market Garden, September 1944).

Mine's a 2001 - W215 - CL500. During what must have been a mental blackout/shutdown I reverse connected a backup spare/second battery that I carry around in my car since a few weeks...

Slow discharge of my new Bosch battery

The reason for the second battery is that after leaving the car 3-4 days untouched, the voltage drops just below what is needed to start my car. Alternator supplies a steady 14,0 - 14,1 V (checked in the special Mercedes-menu, on my heater's display) and my battery's a brand new Bosch 90 Ah device.

Anybody an educated hint regarding what's drawing a current and draining my battery???

I first found a CD stuck between the in-cartridge position and the position in which it can be played. I thought I had found the culprit; the small CD-transportation electric motor being actuated constantly since neither end-position switch indicates 'CD in cartridge' or 'CD in playing position'... After sorting the CD-changer, the slow discharging of my battery still occurs...

Reverse connected spare battery

The symptoms were identical to what Fast28 described some years ago (reverse connected battery too):

- Wiper blades funtioning inceasantly
- Bose sound system dead
- Comand system dead
- Starter motor disabled
- Dashboard stayed black
- All kinds of electronic stuff disabled

After disconnecting the second reverse connected battery and charging the new in-car Bosch battery:

- Starter motor back online
- No spark
- Some problems solved, some still there

After sorting some 4-5 fuses in the standard fuse boxes and in the Bose amplifier:

- Engine starts
- Most electronic devices back online
- Comand & Bose sound system back online
- Alternator DOES NOT WORK; problem remedied after reading Fast28's post and replacing the 150 A MIDI fuse in the passenger's foot well (just pulled back the carpet, no disassembly of the plastic sill cover needed...)


- ABS, BAS, ESP fault codes in central display
- ABC fault code in central display (color = white, system works normally)
- ABS fault bulb lights up in the right side section of my dash
- Distronic fault code in central display
- Braking lights ON constantly (without me touching the brake pedal)

So I ordered a replacement used CPU module ABS-BAS-ESP-PML from Ebay. Installed it. Problems still there...


1) Fast28 mentions the fuse box located over the battery, behind the trunk carpet/cladding, but he did not mention replacing any fuses there. Should I go there and replace (a) fuse(s) to solve my remaining problems?

2) Isn't it necessary to have the local Mercedes dealer reset the fault codes in my car? Or do they go away automatically after solving all problems / changing broken fuses / replacing the ABS-BAS-ESP-PML CPU?

3) Any other tips?

Sure hope anybody here, can help me fix my car... Don't even wanna think about a Mercedes-invoice for several hours of searching and finding nothing and/or with a quote for several hundreds/thousands €'s worth to make me a happy -driving- bunny again...

Regards, Christiaan


Senior Member
Oct 13, 2013
Reaction score
Your Mercedes
97' C250TD Sport
Hopefully someone like @star @WG-MB & Steve from Avantgarde Automotive can help you mate.

Welwyn Merx Limited is a family run business with genuine passion, dedication and 25 years of experience dealing with Mercedes-Benz and AMG passenger cars.
Tel: 01707
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