DISTRIBUTORLESS Ignition (Dis) Module
The main function of the DIS module is to switch between ignition coils and trigger coils to spark. The DIS module receives the PIP and CID signals from the crankshaft timing sensor, and the Spark Output (SPOUT) signal from EEC-IV module.
During normal operation, PIP is passed on to the EEC-IV module and provides base timing and RPM information. The CID signal provides the DIS ignition module with information required to switch between coils for cylinders No. 1 and 4 and the coils for cylinders No. 2 and 3. The SPOUT signal contains the optimum spark timing and dwell time information. The dwell time is controlled or varied by varying duty cycle (duration) of SPOUT signal. This feature is called Computer Controlled Dwell (CCD).
With proper inputs of PIP, CID and SPOUT, the DIS ignition module turns the ignition coils on and off in the proper sequence for spark control. See Fig 1.