The Powertrain Control
Module (PCM) is the control center of the vehicle.  It controls the following
 items:
|     •  | Transaxle/transmission shifting. | 
 
|     •  | On-board diagnostics for powertrain functions. | 
 
It 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. It 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.