Aurora V6-214 3.5L VIN H SFI (2001)
Powertrain Control Module: Description and Operation
Torque Management
The torque management is a function of the PCM that reduces engine power under certain conditions.
Torque management is performed for 3 reasons:
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To prevent any overstress of the powertrain components
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To limit the engine power when the brakes are applied
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To prevent any damage to the vehicle during certain abusive maneuvers.
The PCM uses the following data to calculate engine output torque:
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The manifold vacuum
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The intake air temperature
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The spark retard
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The engine speed
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The engine coolant temperature
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The A/C clutch status
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The EGR valve position
The PCM then looks at the torque converter status, the transaxle gear ratio, and the brake switch inputs and determines if any torque reduction is
required. If a torque reduction is required, the PCM retards the spark as appropriate to reduce the engine torque output. In the case of abusive maneuvers,
the PCM may also shut off the fuel to certain cylinders to reduce the engine power.
The following are 4 instances when engine power reduction is likely to be experienced
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During transaxle upshifts and downshifts
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During heavy acceleration from a standing start
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If the brakes are applied with a moderate to heavy throttle.
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When the driver is performing stress-inducing or 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 cases, the engine power output will be moderate
at full throttle.
When the PCM determines that an engine power reduction is required, it 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 will momentarily disable the
fuel injectors to obtain the necessary amount of torque reduction.
