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How to remove C240 ECU

How to remove the ECU from a 2001 to 2005 Mercedes C240

The ECU (engine control unit) for the C240 is located under the hood in the engine compartment. It is seated in a vertical position with the 5 plugs facing upward. The black box that contains the unit is quite visible upon lifting the hood. As you face the car, the box is against the compartment wall just beneath the driver's side windshield. An irregularly shaped, relatively lightweight black cover protects the contents of the box and it can easily be lifted off by hand. Put the cover aside for the moment and you will clearly see how to remove the ecu. This is also a good time to check for any water damage. Beneath it you will observe on the side nearest you two buckles. These are to be snapped down to open the box. The lid of the box can then be worked free to reveal fuses and brightly colored wires. The wires consist of five slotted plugswater damage unit which run directly into the engine control unit (ME), which sits on its side in a two to three-inch slot to the far right of the box.There are a total of 5 plugs that go into the C240 ecu. Each plug has a safety latch that slides over. You will have to flip the safety latch for each plug in order to remove them from the (ME). The plugs are to be removed from the ME according to a careful mapping of their color-coded arrangement. It is perhaps a good idea to take some photographs prior to removing the plugs from the engine control module. In this way, you will be able to keep them in the proper order, which is quite crucial. When installing the new ecu you can't get the plugs mixed up because they will only plug into one slot each. The engine control unit will slide directly out of the box. You may then write down or photograph the Mercedes part number on the ecu so that we can provide you with the correct replacement part. The part number should look somethingwater damaged ecm like this A1121530879 The new ecu we provide can then be returned to the slot from which it was removed and the wires reattached in the original sequence.

One you install the new unit it will be plug and play. Fully programmed to your vehicle and Mercedes smart key. No dealer trips necessary

If you need additional help on how to remove the ecu watch this video