Idle high

Hi and thanks for using 2CarPros.com.

First, a high idle can be caused by a few things. Can you tell me what was already done?

Here is a general link which describes possible reasons for a high idle:

https://www.2carpros.com/articles/engine-idles-too-high

Here is a link which shows how to replace an idle air control motor. Look through it to better understand its function.

First, here are directions from alldata discussing checking the idle speed. Follow these directions to see if the vehicle fails.

Idle Speed Inspection

NOTE:
- Before checking the idle speed, check these items:
- The malfunction indicator lamp (MIL) has not been reported on, and there are no DTCs.
- Ignition timing
- Spark plugs
- Air cleaner
- PCV system

- Apply the parking brake, and make sure the headlights are off.

1. Disconnect the evaporative emission (EVAP) canister purge valve connector.
2. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
3. Make sure the HDS communicates with the ECM/PCM and other vehicle systems. If it doesn't, go to the DLC circuit troubleshooting. See: Data Link Connector > Component Tests and General Diagnostics > DLC Circuit Troubleshooting
4. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
5. Check the idle speed without load conditions: headlights, blower fan, radiator fan, and air conditioner off.
6. let the engine idle for 1 minute with high electric load (A/C switch on, temperature set to max cool, blower fan on high, and headlights on high beam).
NOTE: If the idle speed is not within specification, do the ECM/PCM idle learn procedure. If the idle speed is still not within specification, go to symptom troubleshooting. See: Computers and Control Systems > Symptom Related Diagnostic Procedures
7. Reconnect the EVAP canister purge valve connector.
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The first three pictures correlate with these directions.

Here are the relearn directions for engine idle speed. It will require a scanner / HDS

ECM/PCM Idle Learn Procedure
The idle learn procedure must be done so the ECM/PCM can learn the engine idle characteristics.
Do the idle learn procedure whenever you do any of these actions:
- Replace ECM/PCM.
- Reset ECM/PCM.
- Update ECM/PCM.
- Replace or clean the throttle body.
NOTE: Erasing DTCs with the HDS does not require you to do the idle learn procedure.
Procedure
1. Make sure all electrical items (A/C, audio, lights, etc.) are off.
2. Reset the ECM/PCM with the HDS.
3. Turn the ignition switch ON (II), and wait 2 seconds.
4. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 194 °F (90 °C).
5. Let the engine idle for about 5 minutes with the throttle fully closed.
NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.
6. Verify on the HDS data list that the idle learn procedure is complete.

Let me know if this helps or if you have other questions.

Take care,
Joe

This sounds like the throttle body and throttle pedal sensor are losing there correlation and the computer is trying to compensate. Have you scanned it for codes? I would service the throttle bore, disconnect you battery first. Here are two guides that can help:

https://www.2carpros.com/articles/throttle-actuator-service

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down these guides and report back.

Cheers, Ken