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2007 S600
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45 Posts
Discussion Starter #1
Interesting problem on this car. The vehicle came to us after visiting several other area MBZ private shops. The ABS Control Unit had been replaced, along with the rear S.A.M. and the brake light switch. Anytime the key was switched on, the brake lights came on and stayed on.

I did not use a very scientific approach to this problem.

Step one (for me) was to check brake light switch adjustment and it was correct.

Next, I pulled the ESP/PML/BAS to look for a bad/corroded connection and noted it was VERY hot to the touch. We had one on the shelf with the same part numbers (031 545 09 32 Q02) so I swapped it in.

Problem solved.

Hope this helps!!!!
 

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17 Posts
Interesting problem on this car. The vehicle came to us after visiting several other area MBZ private shops. The ABS Control Unit had been replaced, along with the rear S.A.M. and the brake light switch. Anytime the key was switched on, the brake lights came on and stayed on.

I did not use a very scientific approach to this problem.

Step one (for me) was to check brake light switch adjustment and it was correct.

Next, I pulled the ESP/PML/BAS to look for a bad/corroded connection and noted it was VERY hot to the touch. We had one on the shelf with the same part numbers (031 545 09 32 Q02) so I swapped it in.

Problem solved.

Hope this helps!!!!
I have same problem, changed Switch and ESP/PML/BAS but not luck. Can you help?
 

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2007 S600
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45 Posts
Discussion Starter #4
It’s a CL500 C215
First things first....check the fuses for the ESP. On a W220, that would be fuses #2 and #34. This is the #1 cause - and most overlooked reason - for the brake lights coming on and staying on when the ignition is turned on.

The system is designed to activate the brake lamps as a safety feature when one or more components is not operating properly. I have seen several where the fuse failed and that was the only problem. Sometimes, people/shops put a lower rated fuse in the wrong place and there is no electrical fault.

I would check the part number on your control unit to be sure you have the right one. We have not had good fortune with used control units. The ESP in the W220 is about $2,100.00 retail brand new, but I have seen several on E-bay - brand new and in Mercedes-Benz packaging - for around $1,000. There is a brand new on on E-bay right now, still in the box for $500.00.

All the best,

Akbar Service
 

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17 Posts
Hi Akbar,
Just checked fuse #2 (50A) NO POWER TO IT. And can’t find fuse 34 Appreciate your kind help. Regards Minaz
 

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Registered
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17 Posts
First things first....check the fuses for the ESP. On a W220, that would be fuses #2 and #34. This is the #1 cause - and most overlooked reason - for the brake lights coming on and staying on when the ignition is turned on.

The system is designed to activate the brake lamps as a safety feature when one or more components is not operating properly. I have seen several where the fuse failed and that was the only problem. Sometimes, people/shops put a lower rated fuse in the wrong place and there is no electrical fault.

I would check the part number on your control unit to be sure you have the right one. We have not had good fortune with used control units. The ESP in the W220 is about $2,100.00 retail brand new, but I have seen several on E-bay - brand new and in Mercedes-Benz packaging - for around $1,000. There is a brand new on on E-bay right now, still in the box for $500.00.

All the best,

Akbar Service
Hi Akbar,
Just checked fuse #2 (50A) NO POWER TO IT. And can’t find fuse 34 Appreciate your kind help. Regards Minaz
 

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Hi Guys,
Akber was right, I located the other fuse and It’s fixed.
thank you for a cheap Fix, thank you.
 
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