Ignition Module

Rather than a crankshaft position sensor mounted at crankshaft pulley (C(3)I), spark is timed by a signal sent from a crankshaft sensor mounted in side of block. This signal is received by ECM (through ignition module) and is used to trigger each coil at the proper time. In the DIS, each cylinder is paired with the cylinder opposite it in the firing order. The spark occurs simultaneously in the cylinder coming up on the compression stroke and in the cylinder coming up on the exhaust stroke. The process is repeated when the cylinders reverse roles.

Each cylinder pair is fired by its own ignition coil. On the 2.0L, 2.3L and 2.5L engines, cylinders No. 1-4 and 2-3 are paired together. On 2.8L and 3.1L engines, cylinders No. 1-4, 3-6 and 2-5 are paired together.

During cranking (and less than 400 RPM), the ignition module monitors crankshaft sensor synchronization pulse to begin ignition firing sequence (1/4 coil pair). The ignition module is incorporated into the coil pack. See Fig 1-Fig 4 .

Fig 1: 2.0L Direct Ignition System Components

Courtesy of GENERAL MOTORS CORP.

Fig 2: 2.5L Direct Ignition System Components

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Fig 3: 2.8L Direct Ignition System Components

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Fig 4: 2.3L Quad-4 Direct Ignition System Components

Courtesy of GENERAL MOTORS CORP.