Powertrain Control Module (PCM) Description: Notes

2004 Oldsmobile Bravada RWDSECTION Notes
WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Data Link Connector And PCM
GM848016Courtesy of GENERAL MOTORS CORP.

The powertrain control module (PCM) is a precision 32-bit microprocessor and is an essential part of the electronic control system. The PCM (1) is located below the instrument panel (IP) storage compartment. Communication with the PCM is through the data link connector (2) located on the left side below the IP.

The PCM performs the OBD II diagnostic tests of the emission related systems. The PCM supplies a buffered voltage, called reference voltage, to the various information sensors and switches. The PCM controls most components with an electronic switch that completes a ground circuit when turned ON. The electronic switch is commonly referred to as an output driver. The PCM is also responsible for a self-diagnosis function and a fail-safe function.

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