If you drive a vehicle that has automatic transmission, then it uses a downshift solenoid. In a manual transmission vehicle, you are changing the gears; however, in an automatic transmission vehicle it is done automatically using pressurized hydraulic fluid. As a gear shift is needed, the transmission solenoid then sends transmission fluid to the valve body. What this means is that the correct gear is able to be chosen.
Here's where the downshift solenoid comes into play. It is responsible for regulating the process of shifting from a higher to a lower gear. This is an electrical component, so it can fail over time. If it does fail, the worst case scenario is that you won't be able to downshift. The best case scenario is that shifting will be erratic.
You won’t find that a downshift solenoid has a set lifespan, or even an average lifespan. Instead you can buy extra time by following your vehicle’s suggested maintenance schedule when it comes to changing your transmission fluid. By doing this you can help prolong the lifespan of it. As for the downshift solenoid itself, it's not included in routine maintenance so you just have to be aware of warning signs.
As the downshift solenoid reaches the end of its lifespan, a few things may begin to happen. At this point it’s wise to have it looked at by a certified mechanic so they can diagnosis the problem.
You may begin to have issues with downshifting. It may either be erratic downshifting, or it's just not able to at all. As the problem progresses, it will get to the point where you can’t downshift.
Your car may begin to skip gears when it shifts. You will feel this as you're driving, and it can even slip back and forth between various gears. This makes driving dangerous.
Your transmission may become stuck in neutral, making it impossible to drive.
When the gears shift, it could feel as though there is a pause or a delay.
The downshift solenoid is an important component in your car. Although it’s not known for breaking down, because it is an electrical component things can happen. Keep in mind that regular transmission fluid changes can help prolong the lifespan of the downshift solenoid. If you’re experiencing any of the above mentioned symptoms and suspect your downshift solenoid is in need of replacement, get a diagnostic or book a downshift solenoid replacement service with a professional mechanic.