Powertrain Control Module
The PCM receives information from various input devices and uses this information to control the following output devices: shift solenoids, band apply solenoid, TCC solenoid and pressure control solenoid (force motor).
The PCM contains a self-diagnostic system which stores a Diagnostic Trouble Code (DTC) if a failure or problem is present in transmission electronic control system. If a specific failure or problem is present, CHECK TRANS indicator will flash to inform driver of a problem. CHECK TRANS indicator is located on left side of instrument panel, below air vent.
DTCs may be retrieved to determine transmission problem area. For information on retrieving DTCs, see DIAGNOSIS & TESTING . PCM contains a fail-safe system. When a specific failure or problem is present in transmission electronic control system, PCM may go into back-up mode using pre-programmed values, allowing vehicle to be driven.
Vehicle can be driven in back-up mode, but shifting must be done manually. When manually shifting transmission, if shift lever is placed in "D" or "3" position, transmission remains in 4th gear. If shift lever is placed in "2" position, transmission remains in 3rd gear. If shift lever is placed in "L" position, transmission remains in 1st gear. If shift lever is placed in "R" position, transmission will shift into reverse. Back-up mode may be cleared by turning ignition off, then back on again.
For additional information on self-diagnostic system, see DIAGNOSIS & TESTING . PCM is located below center of instrument panel. See Fig 1 .