Torque Management

Torque management is a function of the PCM that reduces engine power under certain conditions. Torque management is performed for 3 reasons:
^ To prevent overstress of powertrain components.
^ To limit engine power when the brakes are applied.
^ To prevent damage to the vehicle during certain abusive maneuvers.

The PCM uses manifold vacuum, intake air temperature, spark retard, engine speed, engine coolant temperature, A/C clutch status, and EGR valve position to calculate engine output torque. The PCM then monitors the torque converter status, the transaxle gear ratio, and the brake switch inputs and determines if any torque reduction is required. If torque reduction is required, the PCM retards spark as appropriate in order to reduce engine torque output. In the case of abusive maneuvers, the PCM may also shut off fuel to certain cylinders in order to reduce engine power.

There are 4 instances when engine power reduction is likely to be experienced:
^ During transaxle upshifts and downshifts.
^ During heavy acceleration from a standing start.
^ If the brakes are applied with moderate to heavy throttle.
^ When the driver is performing stress-inducing (abusive) maneuvers such as shifting into gear at high throttle angles.

In the first 2 instances, the driver is unlikely to even notice the torque management actions. In the other situations, the engine power output will be moderate at full throttle.

When the PCM determines that engine power reduction is required, the PCM calculates the amount of spark retard necessary to reduce power by the desired amount. This spark retard is then subtracted from the current spark advance. In the case of abusive maneuvers, the PCM momentarily disables fuel injectors in order to obtain the necessary amount of torque reduction.