The Direct Ignition System (DIS) avoids the use of distributors to deliver the ignition spark to the cylinders, using instead the signals produced by the CMP Sensor (Camshaft Position Sensor) or the CKP Sensor (Crankshaft Position Sensor). With this data, the Powertrain Control Module (PCM) determines the most appropriate ignition timing, taking into account the vehicle’s engine speed and load. To achieve the most accurate ignition timing possible, the igniter is used. This also prevents high voltage levels from being lost, thus allowing the service life of these components to be increased.
The cylinders that are connected to the coil receive an ignition signal from the igniter. The PCM determines when it is the most appropriate time to send the ignition signal. After the ignition signal is received by the igniter, it is transmitted to the primary winding so that the coil passes it to the corresponding cylinder.
Although the voltage produced by the spark ignites the fuel mixture, the PCM needs to know the voltage that assists cylinder ignition. For this reason, an IGF (Ignition Feedback) signal is provided to the PCM after the primary signal has been interrupted. If this feedback signal is deficient or its strength is not adequate, the P1315 OBDII diagnostic code will be set