LEMON Manuals: Even more car manuals for everyone
Home >> Oldsmobile >> 1995 >> Aurora >> Repair and Diagnosis >> Engine Performance >> Engine Controls - Adjustments >> Throttle Position (TP) Sensor >> V8 Throttle Position Sensor >> Idle Speed Control (ISC) Check

Idle Speed Control (ISC) Check

  1. Install Tech 1 scan tester. Turn ignition on leaving engine off. Check for diagnostic trouble code(s). Repair any diagnostic trouble code(s) as necessary. See TESTS W/CODES - 4.0L article in this section. Go to next step.
  2. With Tech 1 scan tester still installed, select MISC TEST, ISC SYSTEM F3. Select F3 to retract ISC plunger, and F2 to extend ISC plunger. If ISC plunger operates as specified, go to next step. If ISC plunger does not operate as specified, proceed to related diagnostic trouble code. See TESTS W/CODES - 4.0L article in this section.
  3. Start engine. Select F3 to retract ISC plunger using Tech 1 scan tester. Note engine RPM. If engine RPM is greater than 700 RPM, inspect for intake manifold vacuum leaks. If vacuum leaks are not present, replace throttle body. If engine RPM is less than 700 RPM or stalls, go to next step.
  4. Turn ignition off, then on leaving engine off. Using Tech 1 scan tester, select MISC TEST, ISC SYSTEM F3. Select F3 to retract ISC plunger. Wait 10 seconds, then record TPS minimum idle value. Select F2 to extend ISC plunger. Wait 10 seconds, then record TPS maximum extend value. Subtract TPS minimum idle value from TPS maximum extend value. Record ISC authority, and go to next step.
  5. If recorded value is 10°-11°, ISC is okay. If recorded value is less than 10°, adjust ISC plunger out by turning ISC plunger counterclockwise. Recheck ISC authority. Recorded value should be 10°-11°. Proceed to IDLE LEARN WITHOUT TECH 1 (4.0L) or TP SENSOR/IDLE LEARN WITH TECH 1 (4.0L). If recorded value is greater than 11°, adjust ISC plunger in by turning ISC plunger clockwise. Recheck ISC authority. Recorded value should be 10°-11°. Proceed to IDLE LEARN WITHOUT TECH 1 (4.0L) or TP SENSOR/IDLE LEARN WITH TECH 1 (4.0L).
scientia non olet · About LEMON Manuals