BMW 1 Series E81 E87 LCI N43 118i 143HP ECU Kit DME 7621178 CAS3 Key Automatic

BMW 1 Series E81 E87 LCI N43 118i 143HP ECU Kit DME CAS3 Key Automatic is a set from the Electronic control modules and controllers group, designed for the N43 petrol engine in the 118i version with an automatic transmission. The kit includes the DME controller along with the CAS3 module and a matched key, which significantly facilitates the professional replacement of powertrain electronics in BMW 1 Series facelift (E81/E87 LCI) vehicles.

Specifications and technical data

• SKU: 7621178-2
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7621178
• Substitutable numbers: 12147640015, 7640015, 12147621178, 7621178, 5WK94901, 61359262361, 9262361
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the DME CAS3 + key kit

The presented set is designed as the central control element for the powertrain in the BMW 118i model with an N43 engine and automatic transmission. Combining the DME engine computer with the CAS3 module and the key ensures the consistency of the authorization, starting, and engine management systems for the petrol engine, which is crucial when replacing a used controller in a new vehicle. In practice, this means the ability to restore the complete communication path between the engine electronics, immobilizer, and starting system without the need for tedious matching of individual components. This solution is particularly valued in workshops specializing in BMW electronics, where the repeatability of the result and operational stability after repair are paramount.

Benefits of using an original BMW kit

The DME kit with CAS3 and key comes from the original BMW production line, which translates into maintaining factory engine control logic and cooperation with other modules in the vehicle. Using an original controller in a car with an N43 petrol engine allows for maintaining proper injection, ignition, and automatic transmission control strategies, minimizing the risk of communication errors in the vehicle's bus. For the end user, this means stable engine operation, correct functioning of comfort features associated with the CAS3 module, and easier diagnostics in the future, as all parameters are handled in accordance with factory BMW documentation. This is especially important when servicing the vehicle in independent workshops that use professional diagnostic testers.

Integration with the powertrain and vehicle electronics

The engine computer in this set is adapted to work with an automatic transmission, which is important for proper torque control, gear shifting, and safety functions. The CAS3 module is responsible for key authorization, immobilizer operation, and initiating the starting procedure, making the entire system a coherent, logically connected unit. Replacing the DME + CAS3 + key set in a single service process reduces the time required for adaptation and coding, and also reduces the risk of conflicts between individual modules. This is a practical solution for both accident repairs and electronics damage resulting from installation failures or water ingress.

Application in workshop practice

In a service environment, such a set is particularly useful for:

• diagnosing and replacing a damaged engine computer in a BMW 1 Series with an N43 engine,
• troubleshooting vehicle starting problems related to the CAS3 module,
• conversions and repairs of vehicles after collisions where powertrain electronics have been damaged. Thanks to the fact that the set includes a key, it is possible to maintain the consistency of the security system, which facilitates further programming and configuration of the vehicle in accordance with user requirements and BMW standards.

BMW electronic control modules – expansion and service

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as engine controllers, comfort modules, or transmission controllers, check the available parts in the BMW electronic control modules and controllers category. To better plan service work related to electronics in vehicles of this brand, it is worth reading the guide describing a practical approach to repairing modules and controllers – detailed tips can be found in the article Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 series models using dismantled parts?.