Code 30, ISC Actuator Slow Or Inoperative: Notes

Code will set if Codes 21, 22, 24, 26 and 27 are not set, vehicle speed is less than one MPH, TP switch is closed, the difference between actual and desired RPM is 288 RPM or more, engine is not receiving a power steering load and ISC motor is in extend mode for more than 29 seconds and TP sensor indicates a throttle angle of less than 9.2 percent, or if ISC motor is in retract mode for more than 29 seconds and TP sensor indicates a throttle angle greater than 1.2 percent.

1. Checks for ISC codes that can cause other problems.
2. Checks if cruise control is engaged causing idle problems.
3. Checks for proper ISC motor operation.
4. Many engine fuel and emissions system faults may cause unstable idle. If the base engine idle is not steady, the ISC may not be able to control idle to within the range of commanded idle speed.
5. Checks PCM's ability to control ISC motor by checking for signal present at ISC motor.
6. Checks for an open or shorted to ground in ISC high or low circuits.
7. Checks PCM's ability to control the ISC motor by checking for signal present at ISC motor.
8. Checks if ISC motor is receiving the signal and is not responding to it correctly. Voltage should fluctuate continuously between negative and positive value.