What causes the throttle body to chatter when key is activated?

Yes, it is recommended to perform a throttle body adaptation or reset procedure after cleaning the throttle body on a 2010 Volvo XC60. This is because cleaning the throttle body can remove built-up carbon deposits and change the air flow through the throttle body, which can affect the engine's idle speed and performance.
To perform the adaptation or reset procedure, follow these steps:

1. Reinstall the cleaned throttle body and reconnect all electrical connectors and hoses.
2. Turn the ignition key to the "On" position, but do not start the engine.
3. Wait for 30 seconds to allow the throttle body to initialize.
4. Turn off the ignition key and wait for 10 seconds.
5. Start the engine and let it idle for 10 minutes with all electrical accessories turned off.
6. Turn off the engine and wait for 10 seconds.
7. Restart the engine and take it for a test drive to ensure proper idle speed and performance.

If the engine still does not idle well after performing the throttle body reset procedure, there may be other issues causing the problem, such as a vacuum leak or a faulty sensor.

You'll have to figure out if you are loosing fuel to the injectors or spark to the plugs to proceed. If it stalls when you come to a stop it could be a dirty throttle body or a faulty idle air control valve.
If you can hold the throttle open and keep it from stalling check the throttle body. If it stops like you turn the key off, you'll have to troubleshoot it like a no start condition.

Hello! Change the Fuel Pump Relay...The prime contacts are defective..They are single pole double throw and normally closed for several seconds to prime the pump and then swing open applying battery to the fuel pump on the normally open side...The chatter is that set of contacts not breaking free from their normally closed position...The result is a unprimed fuel pump (which you are priming with gas into the throttle body....That plus the noise...Guru...saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Do you mean that the engine shuts off when you come to a stop? If so, you need to have the throttle body cleaned, grime build up in the throttle body will cause a lean condition. This shutting off happens especially with the AC on.

It means that the throttle body is dirty and the deposits in the throttle bores are restricting air flow at idle to the point that the idle speed control has no more authority to maintain the correct idle speed.

Take the air cleaner off, hold the throttle wide open and look down the throttle bores. Spray the throttle bores with carb cleaner and scrub the bores and backside of the throttle blades with an old toothbrush. Cleaning the deposits off the bores and throttle blade backsides it will restore the idle air flow to the correct level. When the throttle body is clean, disconnect the battery negative cable for 60 seconds to reset the idle learn offsets to the "clean throttle body" default values.

While you are in the throttle body and looking down the bores....see the two tubes sticking up at you from the intake manifold floor just below the throttle blades...??? Those are the EGR tubes and they are NOT supposed to be full of carbon and crud. Rod them out thoroughly with a piece of stiff wire to remove the deposits. Go all the way down thru the tubes to the cast passage below and make sure that they are clean and unrestricted so that the proper amount of EGR can flow.

Turning the key to the run position extends the ISC anticipating a restart, so if the setting is incorrect it would not erase a hard code. Just turning the key to run would light up both the service soon and service now lights as a bulb check, in other words, letting you know the bulbs work. Do you have the factory service manual?

The ISC adjustment is simple on this car. With the engine running and at operating temperature, You raise the throttle arm slightly with your right hand and push the shaft of the ISC in to fully retract it with your left hand. With constant pressure on the ISC shaft it will slowly retract. The very second it bottoms, you quickly remove the wiring connector to the ISC. Now you should have a very low idle and a gap between the throttle arm and the tip of the ISC. Approx. 0.060 of an inch. Once you know the gap is correct, shut off the engine, wait 10 seconds and reconnect the ISC wiring. Restart the engine and the ISC is set to spec. The TPS setting must be verified at this time. At minimum idle, ISC not touching the throttle arm, and unplugged, the TPS should be reading approx .0 or .1. Once the ISC is reconnected, you should see a TPS reading of approx. .5 at idle. with the A/C off.

A hard code can be erased but will continue to reset as long as the reason for it has not been corrected. Idle learn procedures were designed into later year engines with multi port fuel injection to adjust idle regardless of the amount of coke build up within the throttle body. Your fuel injection system does not build up coke or deposits because the 2 injectors spray down thru the throttle body, effectively cleaning the throttle body while running. Alot of owners adjust the ISC as if it were a throttle stop screw on a carb. guessing as they go. The ISC and TPS "MUST" be in sync to get the best off throttle response and smoothest idle. Adjusting the ISC without verifying gap or TPS voltage usually results in a surging or too high warm idle. You say the car failed at idle. For what reason? CO or HC? or idle too high?

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I have a 2003 Chevy Avalanche 1500 Z71 4X4. What you describe happened to me (6) times last week. #1, I replaced the ignition switch, $32.00. The issue happened again last night and recorded the code P1514 (Throttle Body performance condition). #2, I cleaned the MAF (mass airflow sensor) and the throttle body. These parts require specific cleaners, which can be purchased at any parts store. Truck runs like new. Best regards, Mike Pyne

im assuming the reduced power message comes on where the odometer is, try cleaning the throttle body with some throttle body spray cleaner.the carbon build up in the t.b.i. will cause false throttle position sensor readings .if indeed the reduced power warning is coming on and cleaning the t.b.i. does not rectify the problem, the throttle body may need to be replaced. approx. 100.00 at kragen,auto zone,ect

The idle air control valve may be dirty with carbon and not working properly. You can try cleaning out the throttle body with two cans of throttle body cleaner, make sure you follow the instructions on the can and do not use carb cleaner. The carb cleaner is to corrosive to the gaskets used in throttle body's. Try to clean out the passage way to the idle air control valve at the throttle body. Once the throttle body has been cleaned and the instructions have been followed, you can reset the idle air control valve by turning the ignition keys to the on position for 30 seconds and then turn the keys to the off position then on for 10 seconds and then start. The engine may idle high then come down, wait for it to come down and idle for 1 min then go out for a test drive. that should fix the problem. If not try resetting the idle air control valve again. Good luck and keep me posted, most of the time it's a dirty or bad idle air control valve at the throttle body. 

check throttle position sensor!! at throttle plate on side of throttle body.

There is a technical service bulletin that may apply to your problem the no. is 09-8-9

ISSUE: Some 2005-2009 Escape Hybrid and 2006-2009 Mariner Hybrid vehicles may exhibit an intermittent Red Triangle On and Stop Safely Now message displayed on the message center accompanied by a sudden RPM loss/no start symptom with a diagnostic trouble code (DTC) P1A0C. Vehicles may exhibit this symptom on the first start of the morning or after an extended idle. The symptom will clear on the next key cycle.
ACTION: Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE For vehicles outside the new vehicle limited warranty, if diagnostics lead to replacing the throttle body you may use this procedure to clean the throttle body as an alternative to replacing it. This procedure is not covered by the new vehicle limited warranty. NOTE: THIS CLEANING PROCEDURE CAN ONLY BE USED ON NON-COATED THROTTLE BODIES. Refer to Workshop Manual, Section 303-04C Removal and Installation - Throttle Body.

1. Remove the throttle body.
2. With the throttle body positioned to the side, open the throttle plate.
3. Using Motorcraft® Choke and Linkage Cleaner or equivalent, spray the throttle body plate and bore.
4. Using a suitable (nylon) brush, clean the edges of the throttle plate and the mating surface of the throttle bore to remove all carbon build up.
5. Reapply Motorcraft® Choke and Linkage Cleaner or equivalent and wipe clean with a lint-free cloth.
6. Remove old throttle body gasket and discard. Install a new throttle body gasket.
7. Install the throttle body.

PART NUMBER PART NAME PM-14 Motorcraft® Choke and Linkage Cleaner