Information Bus: Description and Operation

Data Communications Link (DCL) Network:

The Data Communications Link (DCL) is a wiring system that allows the sharing of information between the Electronic Engine Control System (EEC-IV), the Message Center Control Assembly (MCCA) and the Cluster Control Assembly (CCA) located in the electronic instrument cluster panel by using a common link (DCL).

The EEC-IV system transmits the following information through the DCL to the CCA and MCCA:
1. Engine RPM.
2. Engine coolant temperature.
3. EEC-IV malfunction indication.
4. Fuel used.

The CCA transmits the following information through the DCL to the MCCA:
1. Fuel level.
2. Odometer.
3. Speed pulses.
4. English/Metric mode.
5. Vehicle in Accessory/Run (ACC/RUN) mode.
6. Charging system warning.

All EEC-IV strategies use the DCL system to transmit Malfunction Indicator Lamp (MIL) information to the MCCA. The MCCA uses MIL information to generate a CHECK ENGINE warning in the event of an engine sensor failure.