The P2784 code indicates a correlation error between the Input Turbine Speed sensors (typically Sensor A and Sensor B). The engine control module monitors both sensors to ensure they report consistent speed data; when the readings differ beyond a calibrated threshold, this code is triggered.
One of the input turbine speed sensors has an internal electrical failure or a worn magnetic element.
Frayed, shorted, or corroded wiring between the sensors and the control module causing signal interference.
Metal debris or sludge buildup on the sensor tips causing inaccurate speed readings.
Worn turbine gears or shaft components causing actual physical variance in speed readings.
An internal fault in the control module's processing circuit for speed sensor inputs.
Low fluid generally causes slipping or pressure codes, but extreme fluid degradation or contamination can foul the sensors and trigger a correlation error.
No. It is highly uncommon for the PCM to be the cause of a correlation error; the issue is almost always a failed sensor, wiring fault, or internal mechanical wear.
The vehicle may be drivable, but operating in limp mode or with erratic shifting can cause accelerated wear on internal transmission components.