Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ignition System - Direct: Description
The Direct Ignition System (DIS) eliminates the need for the conventional distributor. The DIS ignition system consists of 2 or 3 separate ignition coils, a DIS ignition module, a crankshaft position sensor, wiring harness and the Electronic Spark Timing (EST) portion of the Electronic Control Module (ECM).
This system utilizes the EST signal from the ECM to control spark timing. Ignition timing is controlled by the ECM, using information from the following inputs: crankshaft position, engine RPM, engine temperature, engine load (manifold pressure or vacuum), air temperature and atmospheric pressure.
In the direct ignition system, each cylinder is paired with the cylinder opposite it in the firing order. On 2.8L engines, cylinders No. 1-4, 3-6 and 2-5 are paired together.
The spark occurs simultaneously in the cylinder coming up on the compression stroke and in the cylinder coming down on the exhaust stroke. The process is repeated when the cylinders reverse roles. Each cylinder pair is fired by its own ignition coil.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.