Diagnostic Aids
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
A short to ground on Yellow wire or Brown wire between ECM and throttle actuator control module will set P1515 and P1516. If either circuit is open, P1516 will set.
The REDUCED POWER lamp will illuminate and the engine will default to the default throttle authority limp home mode.
Using the scan tool, command idle speed throughout RPM range to ensure smooth throttle operation and response. If throttle plate binds in any position, replace the throttle body.