Please match the following 0 261 209 290. We recommend matching the following but believe your MB shop can update this: A 273 153 66 91

• You must match your part number exactly as seen above. If any numbers are off compared to your original it will not work properly.
• Ecu will require programming or coding to your vehicle or vehicle's security system and is not plug and play. You will need to take this to your local BMW/Mercedes/VW "IMPORT SHOP" for programming. Your dealer will more than likely refuse to perform the programming or say it can't be done.
• Ecu will fit 2008 CLK550 AND CLS550 models with an exact part number match. May fit 07 models but again match your part number.

ECU has been tested with our state of the art vehicle simulator which tests over 25 circuits of the ECU! Some of those are listed below:

ECU has been tested with our state of the art vehicle simulator which tests over 25 circuits of the ECU! Some of those are listed below:

• Reference Voltage Good!
• ECU powered up and has communication!
• ECU fuel pump/main relay test good!
• The problem areas on the PCB that cause a no crank with the cooling fan running have been tested good or repaired.
• ECU injectors/coils circuits test good

• Disconnect the negative terminal of the battery. Make sure the battery connector is not touching the battery post.
• Disconnect and remove the module to be replaced.
• Install and connect the replacement module.
• Connect the negative terminal of the battery.
• Ecu will now need programming or coding to your vehicle.

• Pins perfect, none are broken or bent
• Mounting tips/pins may or may not be included. You can easily swap the mounting pins from yours onto this working unit prior to install.

This ECM comes with a 90 day warranty from the date of purchase. Please keep a copy of your purchase record which we will send with your item.

If you would like to send your ecu back for a $35 core refund please let us know during checkout and we will include a prepaid return label with your purchase. Once the core returns we will issue your partial refund promptly. It's that simple. This is optional and you are not obligated to participate.