Code P027, Open Throttle Position Switch Signal: Action

WARNING: This page is about a different car, the 1995 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.

PCM turns on MIL and disables EGR.

NOTE: Test numbers refer to numbers on diagnostic chart.

PCM harness connector to ISC jumper is located between generator and cruise control servo.
ISC jumper is a separate harness that connects the ISC to PCM harness.