5 common causes of a car that won't go in reverse

Car transmissions have advanced by leaps and bounds since the auto industry's earliest days. A vehicle's gearbox is typically one of its hardiest components and won't break easily. That said, if you find yourself in a sweet parking spot and you suddenly find your car won't go in reverse, what can you do? It can come out of nowhere, and you need to understand why it can happen to you.

Different transmissions use different architecture, depending on if it's a manual or an automatic. Some problems are specific to either, but other issues can plague both. Whether you drive a Ford, a Kia, or a Volkswagen, these issues can arise with any vehicle at any time. So, it's best to understand why a car won't go in reverse from all points of view.

• Defective transmission position sensor - Automatic cars have shift levers that let you put the vehicle in park, reverse, neutral, drive, and sometimes sport mode. When you engage the shift lever, an electronic sensor detects movement and lets the powertrain control module know the proper position. If this sensor is faulty, you may not be able to shift to any mode, let alone reverse. Should you suspect this on your car, inspect the dashboard for the check engine light or use an on-board diagnostics (OBD) tool to know for sure.

• Deteriorated valve body - A valve body is a component in automatic transmissions that looks like a maze or circuit board but is cast in metal and serves a different purpose. This part exists to help ensure the smooth flow of hydraulic fluids into the valves. When it functions well, the valve body allows the transmission to shift without a hitch. When the valve body is damaged or worn out, you may experience delayed shifts or even failure to go in reverse.

• Worn-out lockout ring - The lockout ring helps prevent untoward shifts when the car is moving forward. This part is what denies the transmission from accidentally shifting to a reverse position. If this part becomes damaged or worn out, it may prevent you from going in reverse, even if that's what you intended.

• Malfunctioning shifter mechanism - This is one of the common causes of a manual car that won't go in reverse. If you've been finding it hard to shift through all the gear positions, then you may want to take a look at the shifter mechanism. If something is wrong with it, you may need to replace a part or two, including the shifter cable or bushings.

• Old or low-level transmission fluid - While the number of kilometers may vary depending on who you ask, almost everyone agrees that transmission fluid needs regular replacing. If you find it difficult to shift in reverse position, consider checking when you last restored your transmission fluid. If it's been a long time or the fluid levels are getting low, that's a sign that you need to get on it immediately.

There are many possible reasons why a car won't go in reverse. We've covered five of the most common causes, and these should help you troubleshoot your vehicle if you encounter a problem. Whatever the cause may be, you should stay calm throughout the entire process. 

Don't mess with something you're not familiar with or are not comfortable fixing. If your vehicle won't go in reverse in the middle of a trip, it's better to contact someone. Call a friend, or better yet, roadside assistance—and get your vehicle to a safe place.