If your car won't go in reverse you may immediately think the worst. After all, you need your vehicle to be able to shift gears quickly. When this happened in my car, I immediately looked at a few things—the transmission, gear fluid, and shifting mechanism.
If you ignore this issue, it can lead to unsafe driving conditions. Plus, ignoring this problem can cause your transmission to completely fail, which is an extremely costly fix.
There are many reasons your car won’t go in reverse, whether your vehicle is an automatic or manual transmission. There are usually a few culprits that owners or professional mechanics should look at first, including the transmission, fluid, sensor, shifter mechanism, and gears.
One of the most common causes is transmission fluid. It can cause the transmission to overheat and lead to inefficiencies under the vehicle’s hood.
Although this can seem like a fox that is too easy, addressing this will usually remedy the reverse issue. Furthermore, when drivers check the fluid levels, they can also see if there is dirty fluid, contamination, or leaking fluid under the car. Leaking fluid can indicate further issues, such as a broken head gasket or leaking hydraulic fluid.
If you choose to fix the problem yourself, you can save money—but going to a mechanic ensures the problem is fixed and the transmission is evaluated.
Still, if you opt for a DIY approach, you will first need to consult your manufacturer’s manual to identify what kind of fluid you will need. Once you confirm that, your next step is to locate the filler tube. When that is done, you will need to remove the dipstick and insert a funnel into the tube.
However, if your model does not have a dipstick, check your manual to determine your options. Be careful not to overfill your transmission as that could damage its parts.
Another reason your car won’t go in reverse is a faulty transmission sensor. A sensor signals the drivetrain to shift into reverse—if the sensor is not working correctly, this can prevent the car from moving. Differing from the low fluid levels, which is a user error or mechanical issue, the faulty sensor is an electrical problem that you must address.
Typically, a car owner can fix a bad transmission sensor by evaluating the diagnostic code at a professional mechanic’s office.
Replacing a transmission sensor might seem daunting at first. Nevertheless, it is a straightforward repair if the sensor is on the exterior of the transmission housing underneath your vehicle. An internal sensor is more complicated and is best serviced by a professional.
The third reason your car may not go in reverse is due to dirty transmission fluid. Just like low fluid levels, contaminated fluid can cause the inability to select a gear or go in reverse dirty fluid usually occurs from corrosion, a broken head gasket, or sludge build-up within the transmission.
One of the most common signals of dirty transmission fluid is brown fluid. Black or very dark brown would suggest your transmission fluid is contaminated.
The best way to fix dirty transmission fluid is to drain the contaminated liquid and refill the transmission. This can be a layered process, and there is no guarantee that you will entirely remove the fluid with a fresh supply. In that context, it may be a good idea to opt for a professional cleaning, especially if the problem comes from a broken head gasket.
In an automatic car, the valve body is an integral part of the transmission that helps control the flow of fluid to the valves. If the valve body is damaged or broken down over time, it can prevent the car from shifting gears in an automatic vehicle.
Replacing a transmission valve body is a demanding fix, even for the most experienced mechanic. The price of replacing this component will vary based on the make and model of the car.
However, in some cases, it is detrimental to replace the valve body, as this could prolong transmission problems. With that in mind, your recommended step is to replace or repair the transmission.
The fourth reason why it may be impossible to put your car in reverse is due to a faulty reverse shifting mechanism in a manual vehicle. Although this is not possible in an automatic vehicle, it is a common trouble area for manual transmission.
If the gear is stuck, a broken gear shifter linkage cannot move to the reverse spot. In this case, drivers will have to replace or repair the linkage.
Some shifter mechanism cables are adjustable, which could allow for a temporary fix. Be sure to check your manual to see if this option is possible. However, this is another malfunction ideally left to specialists.
The last reason your car may not be able to reverse is for automatic vehicles only. If your sensor for the transmission range is not working correctly, your gear stick may not move correctly. It is mounted outside the gearbox and controls the gear selection when moving the gear stick.
If this automatic transmission range sensor is not reading the data correctly, it can cause the transmission to stall — in this case, your car will not move.
As there are many potential causes, the best approach to determine the culprit of the issue is to bring your vehicle to a mechanic. They will evaluate the engine control unit and the transmission control module and provide a long-term fix.
Often, fixing your car not being able to go in reverse can be relatively straightforward — although it can sometimes be costly. Drivers should immediately check their fluid, shifting mechanism, and gears when they notice this issue.
Many of these solutions can be done yourself. Still, it is often best to take your vehicle to a professional mechanic. After all, you want to be confident that the source of the issue is identified and fixed.