Torque Management

Some vehicles are programmed with a Torque Management function. The Torque Management is a function of the PCM that reduces engine power under certain conditions. Torque Management is performed for the following reasons:

To prevent overstress of the powertrain components.
To reduce engine power during certain Throttle Actuator Control (TAC) system faults.
To limit the engine power when the brakes are applied more than approximately 40 percent.
To prevent damage to the vehicle during certain abusive maneuvers.

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

Air/Fuel ratio.
Mass Air Flow (MAF).
Manifold Absolute Pressure (MAP).
Intake Air Temperature (IAT).
Spark Advance.
Engine Speed Engine.
Engine Coolant Temperature (ECT).
A/C Clutch Status.

The PCM monitors the torque converter status, the transmission gear ratio, and the extended brake switch input 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 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.
Heavy acceleration from a standing start.
The brakes are applied with moderate to heavy throttle (with the traction system active).
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 two instances. The engine power output will be moderate at full throttle in the other two 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 No. 1, 4, 6, and 7 in the case of an abusive maneuver.