Ford F-150s are as solid as workhorses come, except when they suddenly don’t let you shift into higher gears and struggle to keep up with traffic in a school zone.
Sounds like a bad TCM to us, and we’ve handled plenty of these little circuit boards to tell you that there are many more issues where that came from if you don’t get it reset!
To save your transmission from an untimely demise, we’ll run you through the methods on how to reset your Ford truck’s TCM and get you back behind the wheel in this guide!
How do you reset a Ford F-150 transmission control module (TCM)?
A Ford F-150 transmission control module can be reset by unplugging the negative battery cable under the hood, which will cut power from the TCM and reset all its parameters.
Other Ford models can reset their TCMs by turning the ignition key in a specific pattern and shifting into Park and Sport (S).
If you’re having issues with your F-150’s transmission shifting weirdly, then one of the most common culprits of this is the TCM.
The TCM (transmission control module) controls many different functions of the transmission, and sometimes, all it needs is a simple reset so that all of the shift parameters go back to their default setting.
In the F-150’s case, the most universally known method to reset its TCM is by disconnecting the negative battery cable and letting it drain for a while.
Doing so will shut off all the accessories and electronics, which includes the TCM. This will also cause the TCM’s stored data collected from miles and miles of driving to be completely reset.
There’s another known method of resetting the TCM that only works on certain Ford vehicles, and that is by using the ignition key and the shifter itself in a specific pattern.
What are the methods to reset a Ford F-150 TCM?
A common method to reset a Ford F-150 TCM is by unplugging the negative battery cable, leaving it for about 30 minutes, reconnecting it again, and then starting the truck.
The alternative method for other Ford vehicles is to use the ignition key and the shifter while following a specific pattern.
Main Method: Unplugging the Battery
The main method to reset the transmission control module (TCM) on your Ford F-150 is by simply disconnecting the negative battery cable, which will force the learned parameters stored inside it to be cleared.
Of course, before you do this, ensure that the engine as well as any electronics are turned off to prevent a spike in voltage that may cause damage to the electrical system.
Open Hood
Before disconnecting the battery, you first need to gain access to the engine bay, which can be done by pulling on the “hood latch” inside the cabin to unlock the hood of the truck.
The hood latch may slightly vary in location and appearance depending on the specific generation of your F-150.
The latch will generally be located at the bottom left corner underneath the driver-side dashboard right next to the footrest or directly under the steering wheel. You can also open the door first to gain access to it and see it better.
Pull the hood latch until you hear a clicking sound, which means that the hood has popped up and can now be opened manually in front.
There will be one more latch/lever in front of the hood that you’ll have to reach under and either pull or push towards the side to fully release the hood. After doing so, push the hood up and let the support struts prop it fully open.
Disconnect Negative Battery Cable
After opening up the hood, you can then locate the negative cable on the battery, which will be the black cable indicated with a minus/negative (-) symbol on the side where its terminal is.
To do this safely, we recommend wearing a pair of gloves and using the right-sized ratchet or wrench to loosen the nut on the negative battery terminal.
Once you have disconnected the negative cable and terminal properly, make sure to move it over to a secure place.
Drain Power for 30 Minutes
To make sure that the disconnected battery resets the transmission control module (TCM) properly, you should avoid reconnecting it too early and instead leave it for about 20 to 40 minutes (30 minutes on average).
This will give the electronics of the truck ample time to fully drain, including the TCM, so that their currently saved settings can be reverted to whatever was originally set from the factory.
During this time, you can also consider inspecting the cables and terminals for any signs of damage or corrosion. If necessary, you can clean the terminals to remove any debris or rust that may affect their ability to clean.
In this case, we recommend unplugging the positive battery cable the same way you did with the negative one as well so that both terminals can be cleaned.
Some baking soda and a toothbrush can be used to clean the terminals and then a soft cloth to gently wipe them dry afterward.
Reconnect Negative Battery Cable
After you’ve successfully drained the power from the truck for a while, you can now reconnect the negative battery cable by reversing the earlier steps while using the same tools.
However, if you also removed the positive battery cable for cleaning the terminals, you must reconnect it first before the negative one to avoid causing any electrical short circuits.
Be sure to properly tighten all of the nuts and bolts on the battery terminals so that electricity can properly flow to and from the battery once you start the truck.
Start Truck to Finish TCM Reset
The last step to resetting the TCM is to start the ignition of your F-150 and check if the control panel on the dashboard gives any notifications or updates about the transmission.
At this point, your transmission will have to relearn all your driving habits, which means that you will have to drive your truck in a way that you would want it to adapt to.
Hence, you should avoid driving the truck too aggressively way too early, as you need to make sure that the transmission properly learns according to your throttle input so that it can time and perform shifts more smoothly.
Alternative Method: Using Ignition Key (Select Ford Vehicles)
An alternative method of resetting the TCM that’s known to work on certain Ford vehicles is by using the ignition key. Just to give a disclaimer, this method is not originally intended for the F-150 and may not be effective.
In addition, there may be some slight differences in the steps between each Ford vehicle, such as the exact pattern of turning the ignition key or how long to leave the key in a certain position.
Insert Key in Ignition
To start the TCM reset procedure, insert your Ford keys in the ignition and just leave it there for about 30 seconds. Be sure to not touch any of the electronics inside the vehicle during this step.
Turn Ignition Key to “Run” Position (Secondary Position)
The next step in the procedure is to turn the ignition key to the “Run” position, otherwise known as the “Secondary” position since this also turns on the ignition system as well as the accessories.
This is obviously different from the “Start” position, which actually turns on the engine. We still need to keep the engine off for this step.
This means that you’ll have to turn the ignition key back to its starting position before moving on to the next step.
Shift into Parking Gear (P)
Once done with the first steps of the ignition key, you should shift the gear selector into the parking gear (P).
There should be no electronics turned on while doing this step, which is why we returned the key to its starting position in the ignition.
Turn Ignition On Without Turning On Engine
After putting the vehicle in park, turn the ignition key to the On/Run position without starting the engine itself and leave it there for about 20 seconds.
Turn Ignition Off Then Immediately On
Now that the 20-second wait is up, turn the ignition key to the off position once more and then immediately turn it back to the on position again.
Shift into S (Sport Mode)
The final step is to shift the gear selector into “S”, which means Sport or Sport Mode. This will finish the TCM reset and you will hear a notification sound from the dashboard to confirm that it was successful.
Where is the Ford F-150 TCM located?
The Ford F-150 transmission control module (TCM) can be located inside the housing of the transmission itself. More specifically, you will find it either attached to the shift solenoid or valve body.
The F-150 TCM location may vary depending on the generation, with others being part of the ECM/PCM.
Ford 4R70W TCM Location
The TCM (transmission control module) on a Ford 4R70W transmission is part of the engine/powertrain control module (ECM/PCM) itself, which is located inside the cabin, underneath the dashboard, and behind the passenger-side kick panel.
Ford 6R80 TCM Location
The TCM (transmission control module) on a Ford 6R80 transmission is located on the mechatronic valve body that sits on top of the oil pan.
What is a transmission control module (TCM)?
A transmission control module or “TCM” is an electronic device that’s responsible for controlling automatic transmission systems.
The TCM makes use of different sensors to monitor parameters such as the vehicle speed and throttle input/position to initiate a gearshift at the most optimum time.
An automatic transmission relies on the TCM (transmission control module) to calculate when is the most perfect time to shift under a given driving condition.
Similar to a vehicle’s main ECM/PCM (engine/powertrain control module), the TCM receives data from several sensors in the engine and transmission so that it can properly adapt its parameters while shifting gears.
Some factors that can affect how your TCM performs a shift include the current vehicle speed and the current throttle/gas pedal position.
What this can translate to is that the TCM may allow for a more aggressive shift at higher RPMs if you were to step hard on the gas pedal, while applying only light pressure on the pedal makes the transmission shift earlier to save fuel.
How does a transmission control module (TCM) work?
A transmission control module (TCM) receives signals from several different sensors located in the engine and transmission to determine the most optimum shift timing.
After receiving input signals from the sensors, the TCM sends its own output signal to the transmission to trigger a gearshift.
Input Parameters and Sensors
A TCM (transmission control) module relies on the input parameters/signals sent by different engine sensors and transmission sensors to calculate the most optimum gear to shift to at the moment.
Input parameters vary depending on the sensor, like how a vehicle speed sensor (VSS) would give data about the vehicle’s current speed.
Typically paired with the VSS, you’ll also have the throttle position sensor (TPS) that monitors how far you’re pushing in the gas pedal based on its current position.
Other examples of sensors that can be sources of input parameters for the TCM include the turbine sensor, transmission fluid temperature sensor, and the cruise control module.
Output Parameters
What goes in must come out, and this is true in the case of a normal functioning TCM. After receiving input parameters, the TCM also sends “output parameters” to the different modules in the transmission, the ECM/PCM, and other concerned controllers.
The types of solenoids located within the transmission can include the shift solenoid, torque converter clutch solenoid, and the pressure control solenoid.
The controllers, on the other hand, can refer to different electronic features outside the transmission that can also rely on the TCM’s output parameters, such as the malfunction indicator light (MIL) and the cruise control module.
Using the two examples of controllers above, the TCM may deactivate the cruise control module if you ever engage neutral, or it can activate the malfunctioning indicator light (MIL) if an issue with the transmission is detected.
Symptoms of a Bad Ford F-150 Transmission Control Module (TCM)
A bad Ford F-150 transmission control module (TCM) can have symptoms such as jerky gearshifts, being unable to shift out of neutral or 1st gear, slow acceleration performance, and reduced fuel economy.
Jerky Shifts
One of the most common symptoms that you’ve got a bad TCM on your F-150 is that the truck jerks back and forth between gearshifts.
Jerky shifts can result in an overall rougher and more uncomfortable ride quality, which can also be a safety concern while you’re sharing the road with other vehicles.
A bad TCM can learn and execute bad shifting habits, making your automatic transmission’s shifts seem unpredictable by either upshifting or downshifting abruptly at the wrong time.
Stuck in Neutral/1st Gear
Another thing that you should definitely look out for if you have a bad Ford F-150 TCM is that you may get stuck in either neutral gear or 1st gear.
Of course, if you were to get stuck in neutral, then that’s the quickest way for you to get stranded right where you are. The engine will not be able to engage the transmission and will only rev freely without moving the truck.
However, getting stuck in 1st gear means that while you may be able to move, you will not be able to shift to higher gears and will thus be limited to low-speed driving.
Some people have also experienced getting stuck in higher gears with their transmission, meaning that the car will not be able to downshift and raise the revs, making acceleration a struggle.
Slow Acceleration/Shifts
If you’re experiencing sluggish acceleration out of your F-150 truck, then this can be another sign that your transmission control module (TCM) is failing. But how do you differentiate it from an issue with the engine then?
A good indicator is that the gearshifts themselves will be slower or delayed, causing your F-150 to accelerate slower since the TCM is taking longer than usual to perform the shift.
It may also seem like the engine freely revs for a split second before the gearshift happens as if the transmission is slipping instead of performing a seamless shift.
Reduced Fuel Economy
When you consider all the different symptoms of a bad TCM on an F-150, you’ll also most likely experience a drop in fuel economy as a result of them.
Your truck may consume more fuel during situations when the TCM doesn’t shift properly or shifts way too slowly, causing the engine to be dumped with extra load for not that much speed.
A faulty TCM may allow the engine RPMs to go higher before shifting the transmission even when it’s unnecessary to go that high. Needless to say, your truck will be drinking more fuel if it continues to shift this way.
Frequently Asked Questions (FAQs)
Can you drive with a bad TCM?
You can technically still drive with a bad transmission control module (TCM) depending on the severity, though it’s not advisable since you will risk doing further damage to the transmission that may cause your car to eventually be undrivable.
TCMs handle different parameters that are crucial in performing a shift, and if it ever goes bad, it can negatively affect your vehicle’s performance and your overall driving experience.
What happens when you reset the TCM?
Resetting a TCM means that you’ll be resetting all of the stored data for both the shift pressure and the timing values inside it, essentially reverting your transmission’s learned patterns to their factory settings.
How do I know if my Ford TCM is bad?
To determine if your Ford transmission control module (TCM) has gone bad, you should look out for symptoms such as jerky shifts, getting stuck in neutral or 1st gear, slow acceleration/shifts, and reduced fuel economy.
What causes a bad TCM?
Some of the most common causes of a bad transmission control module (TCM) include a faulty circuit board solenoid, exposure to excessive heat, faulty electrical wiring, and voltage redirecting and overloading the TCM’s circuit board.
A TCM may also go bad if it’s ever exposed to water or moisture, or gets damaged due to excessive vibrations on the vehicle.
