Engine Control Module: Description and Operation

Description:

The Powertrain Control Module (PCM) is the control center of the vehicle. The PCM controls the following items:
^ The fuel metering system
^ The transaxle/transmission shifting
^ The ignition timing
^ The on-board diagnostics for powertrain functions.

The PCM constantly looks at the information from various sensors, and controls the systems that affect vehicle performance. The PCM also performs the diagnostic function of the system. The PCM can recognize operational problems, alert the driver through the MIL, and store diagnostic trouble codes which identify the problem areas to aid the technician in making repairs.

The type of PCM used is a PCM 32U. The knock sensor module is no longer a separate component. The PCM contains integrated knock sensor (KS) diagnostic circuitry. For more information on the integrated KS circuitry, refer to Knock Sensor System.

The PCM verifies that the password received from the theft deterrent controller module via the Class 2 serial data line is correct. The theft deterrent controller module can learn only one enable password. If the enable password is correct, the PCM enables the fuel system and engine starting system.

The PCM disables the fuel and starting systems it any of the following conditions occur:
^ The enable password incorrect
^ The system disable password is sent by the theft deterrent controller module.
^ No passwords are received - there is no communication with the theft deterrent controller module.