Powertrain Control Module

The Powertrain Control Module (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 Fig 1 - Fig 3 . 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 sensor on models equipped with Distributorless Ignition System or distributor on models without DIS, crankshaft position sensor, engine coolant temperature sensor, intake air temperature sensor, logic circuits, manifold absolute pressure sensor and throttle position sensor.

Fig 1: Locating Powertrain Control Module (Dakota & Durango)

Courtesy of CHRYSLER CORP.

Fig 2: Locating Powertrain Control Module (Ram Pickup)

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Fig 3: Locating Powertrain Control Module (Ram Van & Ram Wagon)

Courtesy of CHRYSLER CORP.