What Causes High Shift RPM in the New LaCrosse?

[Jess]

High shift RPM in the New LaCrosse is caused by a faulty throttle position sensor, which sends incorrect signals indicating an open throttle. The ECU then enriches the fuel injection based on these signals. Replacing the position sensor will resolve the issue. Location of the Throttle Position Sensor: The primary function of the throttle position sensor is to detect whether the engine is in idle mode, under load, accelerating, or decelerating. It is essentially a variable resistor with several switches, installed on the throttle body. Function of the Throttle Position Sensor: When the throttle is in the idle position, the idle contact closes, sending an idle condition signal to the ECU. When the throttle is in any other position, the idle contact opens, outputting voltage signals corresponding to different throttle angles. The ECU uses these signal voltages to determine engine load and adjusts fuel injection accordingly or performs fuel cut-off control.