Torque Management

Torque management is a function of the PCM that reduces engine power during certain conditions. Torque management is performed for the following reasons:

• In order to prevent over stressing the powertrain components
• In order to prevent damage to the vehicle during certain abusive maneuvers
• In order to reduce the engine speed when the IAC is out of the normal operating range

The PCM monitors the following sensors and engine parameters in order to calculate the engine output torque:

• The air/fuel ratio
• The mass air flow
• The manifold absolute pressure
• The intake air temperature
• The spark advance
• The engine speed
• The engine coolant temperature
• The A/C clutch status

The PCM monitors the torque converter status, the transmission gear ratio, and the engine speed in order to determine if torque reduction is required. The PCM retards the spark as appropriate, in order to reduce the engine torque output if torque reduction is required. The PCM also shuts off the fuel to certain injectors in order to reduce the engine power in the instance of an abusive maneuver.

The following are instances when an engine power reduction is likely to be experienced:

• During transmission upshifts and downshifts
• During heavy acceleration from a standing start
• If the IAC is out of the normal operating range
• If the driver is performing harsh or abusive maneuvers, such as shifting into gear at high throttle angles or shifting the transmission from reverse to drive in order to create a rocking motion.

The driver is unlikely to notice the torque management actions in the first 2 instances. The engine power output will be moderate at full throttle in the other 2 instances.

The PCM calculates the amount of spark retard that is necessary to reduce the engine power by the desired amount. The PCM disables the fuel injectors for cylinders 1, 4, 6, and 7 if an abusive maneuver occurs.