Powertrain Control Module
WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, 2002 Chevrolet RV Cutaway, and 2002 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) is located in the engine compartment. The PCM is the control center of the vehicle that controls the following:
- The fuel metering system.
- The transmission shifting.
- The ignition timing.
- The on-board diagnostics for powertrain functions.
The PCM supplies either 5 or 12 volts to power various sensors and switches. This is done through resistances in the PCM. The resistance is so high in value that a test light does not illuminate when connected to the circuit. In some cases, even an ordinary shop voltmeter does not give an accurate reading because the voltmeters resistance is too low. Therefore, a DVOM with a minimum of 10 megohms input impedance is required to ensure accurate voltage readings.