Powertrain Control Module (Pcm)

The PCM is a digital computer that controls ignition timing, air/fuel ratio, fuel injector pulse width, ignition coil(s), spark advance, emission control devices, cooling fan, charging system, idle speed, cruise control (if equipped), fuel pump and tachometer. For PCM location, see PCM LOCATION  table. PCM uses data from various input sources to control output devices in order to achieve optimum engine performance for all operating conditions.

PCM has voltage converters that convert battery voltage to regulated 5-volt output. The 5-volt output powers battery temperature sensor, Camshaft Position (CMP) sensor on models equipped with Distributorless Ignition System (DIS) or distributor on models without DIS, Crankshaft Position (CKP) sensor, Engine Coolant Temperature (ECT) sensor, Intake Air Temperature (IAT) sensor, logic circuits, Manifold Absolute Pressure (MAP) sensor, Throttle Position (TP) sensor and Vehicle Speed Sensor (VSS) on some models.