Electronic Ignition System Diagnosis (3.4L): Description

Ignition Control (IC) module has independent power and ground circuits. Circuits between IC module and Powertrain Control Module (PCM) consist of the following circuits:

• IC timing signal.
• IC timing control.
• Low-resolution engine speed signal.
• Low reference signal.

IC module sends 3x signals to PCM. IC module controls timing advance during engine cranking. Timing advance changes to PCM control after the following actions:

• PCM receives the second 3x signal.
• PCM applies 5 volts to IC timing signal circuit.
• Timing advance switches to PCM control.