The Automatic Transmission Will not Allow Car to Move In Any Gear

Your vehicle will run smoothly because of many factors. An important component of the vehicle is its automatic transmission. This transmits the engine's power to the wheels. If the car doesn’t move in any gear of an automatic transmission, you have some issues that need to be dealt with.

In this guide, we look at the reasons you can’t get your car moving. You will also find some tips on how to get it fixed and back on the road. 

Reasons Car Won’t Move in Any Gear (Automatic Transmission)

Leakage or low transmission fluid are the main causes. A clogged filter or leak can cause the car to stop moving. defective transmission control unit, If the clutches are worn out. 

Here’s a more detailed list of why your automatic transmission may not move in gear:

1. Inadequate transmission fluid

A low level of transmission fluid is one of the main causes for transmission troubles. Transmission fluid is necessary to maintain the transmission's ability to shift and allow the vehicle to go forward. 

It’s possible that there’s a transmission fluid leak that needs to be dealt with. Check the level of the transmission fluid dipstick to make sure it is topped off. Also, fix any leaks in the transmission to avoid permanent damage. This would in some cases be the simplest and most cost-effective solution for your car's problems. 

Related: Low transmission fluid symptoms (check the level)

2. Blockage of Transmission Filter

Filter protects the transmission from harmful particles and dust. If you aren’t changing the filter with your regular maintenance, you are allowing the debris to build up inside. This can eventually cause a blocked transmission filter. 

A whining sound can be heard as the filter becomes blocked. While it’s getting worse, you may be able to drive sporadically before it stops again. The transmission filter should be replaced every 3000 miles, or 2 years, depending on when it happens. But check your owner’s manual for the correct intervals for your vehicle.

If you haven’t done this recently and are having transmission issues, this is a good place to start. The fluid can also be changed at this time to maintain your transmission's optimal condition. Thankfully, the transmission fluid change doesn’t cost a lot to accomplish. 

READ MORE: What Does it Cost to Change Transmission Fluids?

3. Bad Shift Solenod or Valve Bodies

The transmission’s valve body contains hydraulic channels where the fluid flows through when the shift solenoids operate. When the transmission fluid becomes dirty, the shift solenoids may become worn down over time. Vibrations will occur when you change gears, if your valve body becomes clogged. You may also experience a car stalling. Once it’s bad enough, the vehicle won’t move at all. 

Sadly replacing a shift solenoid or the valve body isn’t an easy fix. The transmission pan must be removed to finish the job. Be patient. 

READ MORE: 7 Symptoms of a Bad Shift Solenoid (& Replacement Cost)

4. Failed Torque Converter

The torque converter often goes bad because the transmission hasn’t been maintained properly. Bad torque converters can result from using faulty transmission fluid or failing to change the filter. 

You might notice warning signs as the converter fails. You may hear strange sounds at first. These sounds may disappear as your car warms up. It will eventually stall if the conditions get worse. 

A torque converter can be a costly part. It can also be very time-consuming to fix because it requires the transmission to be taken out. Another task that might require a specialist in transmission repair is this. 

5. Wear-Out Clutches

Similar to the manual transmission, an automatic transmission has clutches. The automatic vehicle will stop moving if the clutches fail. When the clutch discs fail, they could cause serious problems. There could be noises during gear changes that can cause the car to stop moving. It is possible that the shifting of gears gets more difficult. 

Changing the worn clutch discs isn’t an easy fix. You will need to remove many parts of the transmission in order to do the job. If you don’t know how to do this, it’s best to get some help. 

6. Bad Gear Position Sensor/Shifter

Problems can arise if the switch or gear position sensor sends an incorrect signal to the transmission controller unit. Your car may not be able to move if it's in the D (or first) gear and TCM is claiming that it's in neutral. However, this is often quite easy to recognize, just look at your car’s dashboard and see if the gearbox matches the gear position.

RELATED: 8 Symptoms of a Bad Automatic Transmission (& Replacement Cost)

7. Defective Transmission Control Unit

Sometimes, the problem with the transmission control unit can be easy to identify because the dashboard may show the wrong gear. When the transmission control unit isn’t working correctly, the car doesn’t seem like it changes gears, even when the RPMs are increasing. You may also experience it not going anywhere. 

However, a failing battery can also lead to this system not working right because it doesn’t have the correct amount of power. To start, make sure your battery is fully charged. 

If that’s not the problem, you might need a new transmission control unit. It can be hard to access these parts and requires a trained technician to fix them. You can ask a professional to take a look if you're not sure.

It is a common mistake, even though it may seem silly.

How to diagnose automatic transmission problems

Here are some tips to help you solve the problem yourself.

1. First, check the transmission fluid. If it’s low, fill it up. 
2. You should check for leaks if the fluid level is too low. To find the source of the leak, place a piece or cardboard underneath the vehicle overnight.
3. If you haven’t replaced the filter, it’s time to perform a transmission fluid and filter change. To check if the filter is clogged,
4. Verify that the shifter is in the correct position and the gear it indicates on the dashboard.
5. Use an OBD2 scanner to read the fault codes and identify any codes that may be related the shifter solenoid or valve body. You can follow the instruction to repair or replace any code related to your transmission.
6. Check the voltage of your battery if nothing else works. If the battery isn’t charged, it can cause trouble with the control unit. 

If you still have not found the issue, then it is time to bring your vehicle in to a professional shop. Specialist transmission technicians can find the problem faster than regular mechanics and have the expertise to fix it. If your vehicle requires a transmission rebuild, this isn’t a task you want to take on at your home garage unless you have a transmission jack and other specialized tools.

RELATED: Should You Repair, Rebuild, or Replace Your Car’s Transmission?

What is an automatic transmission?

Different from the manual transmission, which forces you to switch between gears, an automatic transmission system works differently. Automatic transmissions use sensors to determine when shifting is required and then it does the work for you. There’s no input required from you to keep the car moving.

Hydraulic fluid is what keeps the transmission's gears moving. These are the selections that most automatic cars have.

• Park (P): The gears are locked and the wheels won’t spin.
• Reverse (R), the reverse gear can be engaged so that you are able to drive backwards.
• Neutral (N) - This is a free-spinning mode that releases all the gears and allows the wheels to rotate without the need for power.
• Drive (D): This allows the car to go forward while moving through every gear. 
• Low (Lower): This means the car is kept in the lowest gears. It's ideal for towing, or climbing up steep inclines. 

You can choose to remove the low gear in some cars and switch to a manual (M) mode. You can manual shift your auto transmission with this setting. 

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