Purpose of the System
The instrument cluster is the main driver information display unit. The instrument cluster is made up of the IKE and a display unit. This type of cluster is known as the "high version".
The "high version" cluster is used on the E38 as a standard feature and the E39 and E53 as an option.
The instrument cluster incorporates the five familiar analog gauges along with indicator lights, warning lights and Liquid Crystal Displays.
When introduced, the IKE was mounted externally on the cluster and was replaced as a separate part. The IKE was connected to the cluster via a 46-pin ribbon cable. The external IKE was eliminated in vehicles from 9/97 and the IKE is now integrated into the cluster housing. If the early version requires replacement the integrated IKE will replace the earlier version.
The IKE functions as a gateway between the D, I and K-Busses. The CAN bus was also added from 9/97.
The IKE contains all of the processing electronics for the Instrument Cluster and On-Board Computer. The Instrument Cluster is merely a display unit and performs no processing. On Board Computer data can be displayed in the MID or the matrix display in the cluster.
There is also an EEPROM in the IKE for storage of the Central Coding Key (ZCS).