How to do a Ford throttle body relearn procedure
If you’ve replaced your Ford electronic throttle body or you’ve disconnected the battery, you must do a Ford throttle body relearn to establish a new baseline idle. Starting in early 2000’s, many car makers including Ford started installing fly by wire electronic throttle bodies. In those vehicles, the “gas” pedal isn’t connected to the throttle body by a cable. The pedal simply provides an electronic signal, telling the throttle body how much acceleration you’re requesting. A motor and gear reduction set inside the throttle body opens and closes the throttle plate to accomplish your request.
Over time, carbon buildup can accumulate around the throttle plate, changing it’s “home” position. If the buildup occurs gradually, the PCM “learns” the new home position. But when your battery goes dead or you disconnect it to work on your vehicle, the PCM “forgets” the adapated home position. If you don’t do a relearn procedure, the PCM will “hunt” for a new baseline idle. It will eventually learn it on its own, but it may take over a week of driving, during which time you will experience high and low idle speeds and possibly rough idle.
Here’s a post on how to CLEAN A FORD ELECTRONIC THROTTLE BODY
Here’s the throttle body relearn procedure
Clear the PCM adaptive memory
1) Disconnect the negative battery terminal.
2) Run a jumper wire from the positive battery cable to the now disconnected negative battery cable terminal. NOTE. Do this with the negative cable DISCONNECTED from the battery. The short circuit you’re creating here is designed to drain all power from the capacitors inside the PCM. Leave the jumper connected for about 2-mins.
3) Reconnect the negative battery cable to the battery.
Turn off all electrical accessories before proceeding. Turn off headlights, blower motor, radio, wipers, etc.
4) Turn the key to run and wait for all warning lights to turn off. During the period the PCM will command the throttle body plate to sweep from full open to full close to “learn” the new positions.
5) Start the engine and let it idle for a full 10-mins until it reaches full operating temperature. During this period the idle may be higher than normal. It should slowly drop as the engine heats up. Watch the engine temp gauge and note when it reaches operating temp. Then continue to let it idle for an additional 5 minutes. It will continue to adjust idle during this period.
6) Drive the vehicle at various speed so the PCM learns shift points.
©, 2015 Rick Muscoplat
Posted on by Rick Muscoplat
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