Pcm Code E30, Idle Speed Control CKT Problem: Action

PCM turns on SERVICE ENGINE SOON light for entire key cycle.

NOTE: Test numbers refer to numbers on diagnostic chart.

Checks for proper throttle switch, brake switch and park/neutral switch operation. PCM must receive accurate switch status information in order to control idle.
Checks for proper ISC motor operation.
Many engine fuel and emissions system faults may cause unstable idle. If base engine idle is not steady, ISC may not be able to control idle speed to within 152 RPM of commanded idle speed.