For a complete wiring diagram Refer to Section 8W.The objective of the Idle “Speed Rationality is to monitor the ability to achieve and maintain a steady idle condition. The monitor will judge the functionality of the idle speed control system by monitoring RPM during idle. If RPM does not come within a calibrated deadband of target idle speed, a timer is started. If the timer reaches its maximum threshold without any sign of the RPM trending towards control, a soft failure is generated. When Monitored:With the engine running at idle, MAF less than 250 mg/tdc, air temp greater than -17.8° C (0° F) and less than -7° C (19.4° F) enable after coolant temp greater than 70° C (158° F) or air temp greater than -7° C (19.4° F), coolant temp greater than -7° C (19.4° F) less than 130° C (266° F), canister purge less than 100% duty cycle, and no VSS, MAF/MAP, ECT, TPS, ETC, CRK Sensor DTCs nor any fuel system or injector DTCs.Set Condition:Engine speed is 200 RPM or more above idle speed for 7 seconds. Two Trip Fault. Three good trips to turn off the MIL.Possible CausesAIR INDUCTION SYSTEMPCV SYSTEM LEAKS OR RESTRICTIONSENGINE VACUUM LEAKSTHROTTLE BODYPCMAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).1. ACTIVE DTCIf any other IAC Motor or Throttle Body DTCs are present, they must be diagnosed and repaired before continuing this test.Start the engine.When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.Allow the engine to reach normal operating temperature.With a scan tool, select View DTCs.It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.Is the DTC Active or Pending at this time?YesGo To 2NoRefer to the INTERMITTENT CONDITION Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING). 2. AIR INDUCTION SYSTEMInspect the Air Induction System for the following problems.Restrictions: Dirty Air Cleaner, Foreign material trapped in the air intake tube, etc.Leaks: Air Intake tube connection, Air Cleaner housing, etc.Were any problems found?YesRepair or replace as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE).NoGo To 33. PCV SYSTEMInspect the PCV system for the following problems:Restrictions - sticking valve, collapsed hoses or tubes, obstructed passages or ports, etc.Leaks - cracked or damaged hoses or tubes, poor hose or tube connections, PCV valve stuck open, etc.Were any problems found?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE).NoGo To 44. VACUUM LEAKSWhen the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. Start the engine.Inspect the vehicle for external vacuum leaks.Inspect the engine for internal leaks.Were any vacuum leaks found?YesRepair the vacuum leak as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE).NoGo To 55. THROTTLE BODY OPERATION / IAC MOTOR OPERATIONInspect the throttle body for carbon build up, other restrictions, and a bent throttle plate using a straight edge.If the throttle plate does not close entirely it may be bent and needs to be replaced.Verify that the throttle cable between the Accelerator Pedal and APPS is not binding on ETC equipped vehicles.Verify that the throttle cable between the Accelerator Pedal and Throttle Body is not binding on IAC equipped vehicles.When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death. While the vehicle is running, lightly tap on ETC Motor or IAC Motor where applicable, with your hand, and listen for idle to raise.Were any problems found or did the idle fluctuate while tapping on the ETC Motor or IAC Motor?YesRepair or replace as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE).NoGo To 66. PCMBefore continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.Were there any problems found?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE).NoReplace and program the Powertrain Control Module per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE).