Service functions

Renewing control units 

The following points must be borne in mind when the CAS or the engine control unit are renewed:

• If a CAS control unit is renewed, it must be ordered using the vehicle identification number (VIN). Following installation, that starting value must be adjusted to the engine control unit. This starting value adjustment is performed using the service function "DME - CAS calibration" in the BMW diagnosis system.
• If the engine control unit is renewed, the drive-enable code must be transferred from the CAS to the engine control unit following installation. This procedure is also performed using the service function "DME - CAS adjustment" in the BMW diagnosis system.
• After the adjustment of the EWS and engine control unit, these are mutually linked. It is not possible to replace one of the two control units as a test.

DME - CAS adjustment 

In the case of a new engine control unit, the service function "DME - CAS adjustment" in the BMW diagnosis system is used to read the EWS drive-enable code from the CAS and transfer it into the engine control unit. This means that the engine control unit and the CAS control unit are mutually linked.

If the engine control unit is already linked to the CAS, the service function is used to perform a starting value calibration. This means that the random code calculation between the CAS and the engine control unit is adjusted.

A start calibration is required if there is a variance in the rolling codes caused by the influence of errors in the two control units.

As of EWS4, a start calibration is no longer required.

Locking the remote key/spare key 

The service function "Remote key/Lock/Enable Key" in the BMW diagnosis system can be used to lock or enable remote key keys or spare keys.

The locking is recommended when a remote key or a spare key is lost or stolen. With a locked remote key (or spare key), engine start is not possible. The functions of the remote key are also locked.

A remote key or a spare key can only be locked if the remote key or spare key has been used at least once and it is not inserted in the ignition lock.

To perform the service function, it is required that a valid and enabled remote key or a valid and enabled spare key is detected in the ignition lock.

Activating of a new remote key 

Insert the new remote key in the insertion slot and hold in this position until the remote key locks into place. This can take up to ten seconds. After locking, wait another five seconds. The remote key is then ready for use. If the remote key is a replacement for a lost or defective remote key, the old remote key still has to be blocked using the service function "lock/release" (see above). To use the Car/Key functions, the service function "Personalization number" has to be run.