Torque Management

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

1. To prevent over-stressing the powertrain and driveline components.
2. To prevent damage to the vehicle during certain abusive maneuvers.

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

• The air and fuel ratios
• The mass air flow (MAF) sensor
• The manifold absolute pressure (MAP) sensor
• The intake air temperature (IAT) sensor
• The spark advance
• The engine speed
• The engine coolant temperature (ECT) sensor
• The AC 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 to reduce 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 case of an abusive maneuver.

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

• During transmission upshifts and downshifts
• During heavy acceleration from a standing start
• When the clutch pedal is released too quick under a heavy load
• When 1 set of drive axles loses traction while the other set of drive axles are not moving-For the 4-wheel drive only and in 4WD low
• When 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 to create a rocking motion.

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

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