C15 and C18 – Clean Emissions Module Ignition System


Components for the ignition system

(9) Spark plug

(16) Ignition coil

(51) Ignition wire

(6) ARD head

(51) Ignition wire

(52) Ground point on the ARD combustion head


Typical ARD combustion head

(9) Spark plug

(53) Ground probe

(54) Spark plug electrode

The ARD ignition system has two circuits. The primary circuit is between the ECM and the ignition coil. The secondary circuit is between the ignition coil and the ARD combustion head. The current flow through the primary circuit indicates the condition of the primary circuit and of the secondary circuit. The ECM monitors the current flow through the primary circuit. In this way, the ECM is able to detect problems with the primary circuit and the secondary circuit.

The ECM creates an ignition pulse 12 times each second whenever the engine speed is greater than 500 rpm. Wiring sends the signal to the primary side of the ignition coil. The ignition coil is located on the panel for the electronics on the Clean Emissions Module (CEM).

The ignition coil converts the ignition pulse into a high voltage signal. Ignition wire (51) connects the ignition coil output to the spark plug. The spark plug is threaded into the ARD combustion head. The spark jumps between the spark plug electrode (54) and ground probe (53) inside the ARD combustion head. The spark ignites the air/fuel mixture.

The ground wire ensures that the secondary ignition circuit is complete between the ARD combustion head and the ignition coil. The ground wire runs inside the insulation that is wrapped around ignition wire (51) . The ground wire is connected to two ground points. One ground point (52) is on the ARD combustion head. One ground point is on the panel for the electronics near the ignition transformer.

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