Pcm Code P030 - ISC Rpm Out Of Range: Action

PCM turns on SERVICE ENGINE SOON light.

1. This step checks for ISC motor codes that can cause other problems.
2. This step 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 base engine idle is not steady, ISC may not be able to control idle to within 152 RPM of desired idle. For symptom diagnosis, see TESTS W/O CODES article in this section.
5. This step checks PCM's ability to control ISC motor by checking for signal present at ISC motor.
6. This step checks for open or short to ground in circuit No. 425 or 426.
7. Checks PCM's ability to control ISC motor by checking for signal present at ISC motor.
8. Checks if ISC motor is receiving signal but not responding correctly. Voltage should fluctuate continuously from negative to positive value.

Fig 1: PCM Code P030 Schematic - ISC RPM Out Of Range

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code P030 Flow Chart (1 Of 2) - ISC RPM Out Of Range

Courtesy of GENERAL MOTORS CORP.

Fig 3: PCM Code P030 Flow Chart (2 Of 2) - ISC RPM Out Of Range

Courtesy of GENERAL MOTORS CORP.