Logic module, located inside passenger compartment behind right side kick panel, is digital micro-computer. Input signals generated by various switches and sensors are used by logic module to determine control (output) signals. Output signals control fuel injector pulse width (length of time injector is open), spark advance, ignition coil dwell, idle speed, purge, cooling fan operation and alternator charge rate.

Logic module monitors its own input and output circuits for inconsistencies and any component malfunctions. If fault is found in major system, information concerning this fault is stored in logic module. Stored codes indicate specific problem areas within system. Information can be retrieved as numbered display code.

When logic module receives signal from distributor pick-up, it activates ASD relay in power module, providing power for fuel pump, fuel injector, ignition coil and some circuits of power module. If pick-up signal is absent, ASD relay will not be activated and power will not be provided to fuel pump or ignition coil.

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.

Safety Warning

Logic Module

Use the Manual With the Right Hardware

When to See a Mechanic