Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com

Torque Reduction Control System






DESCRIPTION
In order to minimize shift shock, a torque reduction control system is used. This system temporarily reduces engine torque to improve shift quality by cutting off fuel delivery during ups shifts and retarding ignition timing during downshifts. If torque reduction is not possible, the power train control module (PCM) adjusts line pressure to a pre-programmed amount to reduce shift shock.

TORQUE REDUCE SIGNAL/COOLANT TEMPERATURE SIGNAL
The torque reduce signal/engine coolant temperature signal is generated by the power train control module (PCM). If the engine coolant temperature is below 60°C (140°F), the PCM is always in reduce torque mode. When the engine coolant temperature is above 60°C (140°F), the PCM is placed in reduce torque mode based on the reduce torque signals the PCM receives. This signal helps reduce shift shock by regulating line pressure.