Powertrain Control Module

WARNING: This page is about a different car, the 2002 Mazda Millenia and 2001 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.

PCM receives information from various input devices and uses this information to control solenoids on transaxle valve body for transaxle shifting, shift feel and TCC engagement.

In "D" range, PCM automatically switches driving mode from NORMAL mode to POWER mode depending on driving conditions. PCM will also automatically switch driving mode from NORMAL mode to SLOPE mode to prevent excessive upshifts and downshifts when climbing or descending hills. PCM shift control detects engine load and vehicle speed and chooses optimum gear to be in according to PCM programming.

PCM monitors transaxle operation and contains a self-diagnostic system which will store Diagnostic Trouble Codes (DTC) if a failure or problem exists in electronic control system. If a problem exists, a DTC is set and PCM will deliver a signal to illuminate Malfunction Indicator Light (MIL), and/or HOLD indicator on instrument panel to warn driver. If either MIL or HOLD indicator is illuminated, stored DTCs can be retrieved to determine problem area. See SELF-DIAGNOSTIC SYSTEM . PCM is located under center of instrument panel, in front of center console.