The Chilton manual for the late 90s and early 2000s Durango and RAM says that PCM controls ignition timing and spark advance. I don't understand this, because these motors are equipped with a standard spark-gap distributor. Because of the mechanical timing, the computer timing should be irrelevant.
Can someone please clarify what is going on with these dodge and similar engines?
What is the relationship between the PCM, the distributor system, and actual ignition control?