Electronic Control Unit (Ecu)

On Cherokee, Comanche and Wagoneer models, ECU is located under instrument panel, above accelerator pedal. On Wrangler model, ECU is located behind glove box. The ECU controls fuel injector pulse width and ignition timing based on inputs received from sensors that react to exhaust gas oxygen content, air/fuel temperature, coolant temperature, manifold absolute pressure, battery voltage, crankshaft position (engine speed) and throttle position.

In addition, ECU receives inputs from switches that are triggered by power steering pump output pressure, wide open throttle position (Wrangler model only) and transmission gear selection (A/T only). Battery voltage is also monitored to determine injector pulse width. These sensors and switches are considered ECU inputs.