Engine Management Interface

Engine Management Interface

Other interfaces
The DME control unit requires a number of other signals for engine management.

Brief description of components
The following components for the other interfaces are described:

Accelerator pedal module
The accelerator pedal module detects the position of the accelerator pedal. The DME control unit uses this to calculate the required position of the throttle valve, taking account of other factors.







Clutch module
On vehicles with manual gearboxes, the clutch module at the clutch pedal picks up the clutch position (clutch pressed: clutch switch open; clutch not pressed, clutch switch closed). The clutch module consists of a clutch switch and an electronic evaluation unit.







Brake-light switch
Two switches are built into the brake-light switch: the brake-light switch and the brake-light test switch (redundancy for safety reasons). The signals indicate to the DME control unit whether the brake pedal has been pressed.







DME control unit
There are 3 other sensors on the board in the DME control unit: a temperature sensor, an ambient-pressure sensor as well as a voltage sensor. The temperature sensor provides thermal monitoring of the components in the DME control unit. The ambient pressure is required for calculation of the mixture composition. The ambient pressure falls the higher you go above sea level. The voltage sensor on the board of the DME control unit monitors the power supply via terminal 87.
The DME control unit is connected with the vehicle electrical system via the engine wiring harness and vehicle wiring harness (3 connector chambers).
The DME control unit is connected via the PT-CAN (Powertrain CAN) across a gateway with the remaining bus system.The gateway is the junction box electronics (JBE).







System functions
The following system functions are described:

Electronic vehicle immobilization
The electronic immobiliser is both an anti-theft device and start release. On the MINI, a newly developed electronic immobiliser (4th generation) is introduced. This development uses a new and modern encryption method. Each vehicle is assigned a 128-bit secret code. This secret code is stored in a BMW database. This means that the secret code is only known to BMW. The secret code is programmed and locked in the CAS control unit and the DME control unit. When the secret code is in the control units, it can no longer be deleted or changed. This means that each control unit is assigned to a certain vehicle. The CAS control unit and the EWS control unit mutually identify themselves with the secret number and the same algorithm.
If the identification data is correct, the CAS control unit activates the starter motor via a relay in the control unit. At the same time, the CAS control unit sends the DME control unit a coded release signal (changing code) for the engine start. The DME control unit only enables the engine start if a correct enable signal is received from the CAS control unit. These procedures may result in a slight start delay (up to half a second).

Notes for Service department

General information

NOTE: Procedure in the event of a defective control unit.

If the CAS or DME is defective, a certain procedure must be followed.
The required control unit must be ordered exactly for the vehicle. For this, the vehicle data (vehicle identification number) is required.
An EWS adjustment is not necessary after renewing the control unit.
No liability can be accepted for printing or other errors. Subject to changes of a technical nature