The fault codes can be checked with either a scan tool or the CHECK ENGINE lamp in the dashboard.
The Chrysler fuel injection systems combine electronic spark advance and fuel control. At the center of these systems is a digital, pre-programmed computer, known as the Single Board Engine Controller (SBEC), the Powertrain Control Module (PCM) or as the Electronic Control Unit (ECU). This computer (referred to as engine computer in this section) regulates ignition timing, air-fuel ratio, emission control devices, cooling fan, charging system, idle speed and speed control. It has the ability to update and revise its commands to meet changing operating conditions.
Various sensors provide the input necessary for the engine computer to correctly regulate fuel flow at the injectors. These include the Manifold Absolute Pressure (MAP), Throttle Position Sensor (TPS), oxygen sensor, coolant temperature sensor, charge temperature sensor and vehicle speed sensors.
In addition to the sensors, various switches are used to provide important information to the engine computer. These include the neutral safety switch, air conditioning clutch switch, brake switch and speed control switch. These signals cause the engine computer to change either the fuel flow at the injectors or the ignition timing or both.