In this guide, we’ll discuss one of the most common problems car owners have to face i.e. car won’t move in any gear in automatic transmission. An automatic transmission system is responsible for shifting gears automatically based on the power demands from the engine and the position of the manual lever. However, sometimes problems arise in the components of the automatic transmission system and different sensors that do not allow the PCM to control the shifting of gears efficiently, due to which your car won’t move in drive or reverse in the automatic transmission.
The most common cause of a car won’t move in any gear in an automatic transmission is a low level of transmission fluid. When the transmission fluid level is low, there will not be optimum pressure inside the transmission system, due to which the torque converter and clutch bands will not engage properly. It will disturb the shifting of gears which will prevent your car from moving in any gear. If transmission fluid is old and dirty, the gears may also not shift. Other causes of the car won’t move when in gear include: a bug in PCM software, bad pressure control and shift solenoids of the valve body, blockage of internal passages of the transmission valve body, clogged transmission filter, bad shifter cable or shifter linkage, worn-out clutch pads, and a broken axle.
Also Read: Transmission shifting hard when cold
Table of Contents
Causes of Car Won’t Start In Any Gear Automatic Transmission
1. Check Engine Light Is On
Sometimes, the car won’t after the second gear in an automatic transmission, it may be due to the check engine light. Your first action should be to see if the check engine light or traction control light illuminates on your dashboard. If it is, chances are that the PCM has put your engine in a reduced power mode to protect it from further damage to your engine.
Due to reduced power mode, the PCM will not shift your transmission into the higher gears so that you do not drive your vehicle at higher speeds. You should use the OBD2 scan tool to find trouble codes stored in your engine’s memory.
In my guide on causes of check engine light on, I’ve some troubleshooting steps to deal with the check engine light.
Some guys on forums just recommend clearing the codes and resetting the ECU using a scan tool without fixing the issue. This might resolve your gear shifting issue, but it will only be for a limited time. After driving a few miles, the check engine light will again turn on.
Note: It isn’t necessary that the check engine light is always on. Sometimes, there are trouble codes that do not turn on the check engine light. So, your first action should always be to use the OBD2 scan tool to detect any trouble codes.
2. Dirty or Low Level Of Transmission Fluid
In automatic transmissions, the transmission plays the same role as blood plays in our body.
Transmission fluid has the following functions:
- Transfers power from the flywheel to the transmission via a torque converter
- Engages clutches and bands by passing through the solenoid and valve body channels under pressure
- Lubricates gear train and differential
If the transmission fluid level is low and it fails to perform any of the above functions, your car might not move in any gear in the automatic transmission.
If you haven’t replaced the transmission fluid after driving 30000 miles or 3 years, you should do a transmission flush. If the transmission fluid condition is fine i.e. it has a reddish tint and does not have any foamy texture, you should just add transmission fluid.
Note: If the transmission fluid is reddish-brown or yellow colored, you should change the transmission oil and transmission filter. If transmission fluid is dark black and has suspended particles, avoid transmission flush as it will further damage your transmission.
To check transmission fluid, you’ll find a dipstick under the hood. You would not want to confuse the transmission fluid dipstick with the engine oil dipstick. Both are different. Moreover, you should start the engine and warm it up to its operating temperature before measuring the level of transmission fluid.
Be sure to have a car on flat ground when checking the transmission fluid. Moreover, putting your car in drive, neutral, reverse, then back to park is usually suggested. This will allow transmission oil to reach all the hydraulic channels in the transmission system.
Moreover, make sure that transmission isn’t leaking from the transmission system. If you find spots of transmission fluid on the driveway. After filling the transmission fluid, jack your car up and see if the transmission fluid is leaking from the torque converter, gearbox, or transmission pan.
3. Broken Shifter Cable or Shifter Linkage
A broken or disconnected shifter cable or linkage can prevent your car from moving in any gear in the automatic transmission. If the gear lever moves, but freely or you have little resistance while selecting gears in the gear selector, the chances are that the shifter cable is either broken or disconnected.
The shift cable connects the gear lever to the transmission and allows the transmission to engage a specific gear set by moving it to the proper position. This connection allows the transmission to recognize when the shifter is in a certain gear. By adjusting the gear lever, you’re mechanically switching the different transmission modes, such as low gear mode, sport mode, gear 1, park (P), drive (D) and neutral (N).
You can find the shifter cable by looking underneath the vehicle at the transmission on the driver’s side of it. So, if the linkage or cable of the gear shifter is broken or bent, the PCM will not be able to determine which gear the manual lever is in.
Fixing shifter linkage and cables is a very delicate process as it has to be exactly done based on the engine’s specifications. So, you have to consult the service manual of your vehicle. Also, the torque requirements for tightening of bolts of the shifter level are given so that it does not come loose.
4. Malfunctioning Transmission Range Sensor/Neutral Switch
A malfunctioning transmission range sensor will not be able to coordinate with the position of the gear shifter. For instance, if your gear shifter is in P mode, the malfunctioning transmission range sensor will send wrong signals to the PCM, due to which PCM will think that your car is in D. As a result, your car won’t move.
The transmission range sensor tells the PCM the position of the shift lever so that PCM can interpret the gear position and speed in an automatic transmission system. You’ll find the transmission range sensor outside the transmission case near the shifter linkage. The transmission range sensor is also called a park/neutral safety switch or PRNDL input.
For the exact position of the TR sensor, you can use the service manual of your vehicle. From the service manual by Ford, I found the following schematic showing the position of the transmission range sensor.
If the transmission range sensor is malfunctioning, the OBD2 scan tool will show P0705, P0706 or P0707 error codes. For some vehicles, like Toyota, Cadillac, Chevy, a bad transmission range sensor or neutral position switch can also show the P1780 trouble code.
If the transmission range sensor malfunctions, it will send the wrong information to the transmission control module. As a result, the transmission will not engage in any gear and your car won’t move in the automatic transmission.
5. Bad CV Axle
A bad CV axle can also cause your car not to move in any gear in the automatic transmission. A CV axle is found in FWDs and AWDs. Both left and right wheels have their own CV axles. If your car is making clunking noises as soon as you start an engine, it is an indication of a bad CV axle.
To determine a bad CV axle, put your car in park mode, jack it up and put it on jack stands. Ask your friend to start the car and hold down the brakes. Meanwhile, you watch the axle. Now, ask your friend to put the car in gear and rev it up while still holding down the brakes. Keep in mind, that the brakes of your car should be kept pressed all the time.
If the axle does not spin, it is a transmission issue, which means that the gears in the drivetrain have been damaged. If the CV axle spins but the wheels do not rotate, the CV axle is damaged.
6. Bad Control Solenoids of Valve Body
Bad control solenoids in the valve body of automatic transmission can also be the cause of your car not shifting in any gear. Moreover, the channels in the valve body can also become clogged with junk and debris in dirty transmission fluid.
If you remove the transmission pan, you will find a valve body of your automatic transmission system. Control solenoids in valve bodies are used to adjust the transmission oil pressure, which in turn adjusts the pressure on the clutches to shift gears. The solenoid is controlled by the ECU (Electronic Control Unit).
In the valve body, there is pressure solenoid and shift control solenoids. The pressure control solenoid maintains the desired pressure of oil in the valve body. Shift control solenoids are open and closed to direct the oil through the channels in the valve to shift the gears.
In the below figure, I have shown the valve body and solenoids for Hydra-Matic 4L65-E
- Transmission fluid pressure switch
- 1-2 shift control solenoid
- 2-3 shift control solenoid
- Pressure control solenoid
First, you have to check if the harness connector of any solenoid is damaged. If the harness connector is fine, you should check each solenoid in the valve body.
The control solenoid becomes bad when it is stuck closed or stuck open. This disturbs the flow of transmission fluid through channels of the valve body and affects the gear shifting.
You can watch the below youtube video to test the solenoids of an automatic transmission system:
7. Worn-out Clutches and Bands
Worn-out clutches can slip and can lead to the car not moving in any gear in the automatic transmission.
In automatic transmission systems, the transmission fluid applies pressure on clutches and bands after passing through the channels in the valve body to engage gears. If the clutches slip, they won’t be able to shift gears which will cause your car not to move in any gear in the automatic transmission.
Clutch pads have abrasive material so that they have sufficient grip to apply pressure on different gear sets in the drivetrain. When clutch pads wear out, they start losing their grip, due to which clutches slip and won’t engage the gear.
Replacement of clutches and bands is not an easy task. You have to completely dismantle your transmission to get access to the clutches. So, before proceeding to this step, start troubleshooting with the easy steps.
Steps To Diagnose Automatic Transmission Problems
- First, check the condition of the transmission oil. If it is dirty, change both the transmission oil and transmission filter.
- If the condition of transmission oil is fine, but its level is low, fill it to the recommended level.
- Make sure that the gear lifter linkage and cable are fine, and that the position of the gear shifter matches the gear position on the dashboard.
- Use the OBD2 scan tool to find trouble codes related to the transmission or engine. Sometimes, engine misfires also cause your car not to move in any gear. So, chances are that the problem is with inefficient combustion.
- Check the valve body and control the solenoids of your transmission system.
- Also, check your car battery if your car isn’t moving in any gear in the automatic transmission. If the battery fails to send insufficient voltage, the PCM will not work correctly.