Code P098, High Rpm Park/Neutral-To-Drive/Reverse Shift Under: Notes
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.
ISC
This test monitors idle speed and gear selection from Park or Neutral to Drive or Reverse when throttle is in ISC speed range. If idle speed is greater than desired, PCM will retard spark to reduce engine power and set Code P098.
Primary purpose of this code is to detect an action of the driver that could cause a harsh shift from Park or Neutral to Drive or Reverse. Code can be driver induced by shifting into gear at a throttle angle of less than 20 degrees with throttle depressed. Check for Code P030 as a slow or inoperative Idle Speed Control (ISC) motor may cause code to set.