DTC P0506: Idle Speed Control Rpm Low

NOTE: After each repair, clear DTCs. See CLEARING CODES/PCM RESET PROCEDURE under SELF-DIAGNOSTIC SYSTEM. Turn ignition off and then on. Read DTCs to verify repair is complete. For DLC and PCM connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS .

Using scan tool, read DTCs. If DTC P0506 is present, check for clogged or blocked passages. Repair as necessary. If passages are okay, check for seized stepper motor. Repair as necessary. If stepper motor is okay, check for incorrect fitting of ISC valve. Repair as necessary. If valve is okay, ensure ISC harness and connectors are not damaged and connections are okay. Repair as necessary. If harness and connectors are okay, go to next step.
Start engine and run at idle. Using scan tool, read throttle position values. Ensure values change as throttle position changes. Repair as necessary. If values change, open throttle and check if engine speed increases. If engine speed does not increase, repair as necessary. If engine speed increases, clear DTCs. Turn ignition off and then on. Read DTCs. If DTC P0506 is not present, repair is complete. If DTC P0506 is present, replace PCM.