Avalanche, Sierra, Silverado, C&K Series, 1999-2005

Distributorless Ignition System


The 4.8L, 5.3L, 6.0L and 8.1L engines do not incorporate a distributor to deliver energy from a common coil to the individual spark plugs. The electronic ignition (EI) system is responsible for producing and controlling a high energy secondary spark. This spark is used to ignite the compressed air/fuel mixture at precisely the correct time. This provides optimal performance, fuel economy, and control of exhaust emissions.

This ignition system consists of a separate ignition coil connected to each spark plug by a short secondary wire. The driver modules within each coil assembly are commanded ON/OFF by the powertrain control module (PCM). The PCM primarily uses engine speed and position information from the crankshaft and camshaft position (CMP) sensors to control the sequence, dwell, and timing of the spark.