The notion that the condition of your car battery can affect the performance of your transmission may seem absurd at first. But it actually makes sense when you consider that nearly every shift in modern transmissions is operated electrically via a computer system that is powered by the battery.
A sporadic voltage drop from the battery can be the cause of all sorts of unusual transmission problems. For instance, cases of delayed transmissions shifts or completely missed gears that appear occasionally and resolve themselves (only to reappear again) can be attributed to corroded battery terminals.
Even if your car starts on the first pull, battery corrosion can still lead to transmission problems.
Starting the engine requires a lot more electricity than shifting gears. And bad connections can make good contact when a huge load is applied to the circuit. It seems like the extra current is able to get past the resistance, providing sufficient power to start the engine. Unfortunately, the small amount of current needed to operate transmission solenoids is not always enough to push through the resistance, resulting in poor transmission performance.
How to Fix Transmission Problems Caused by Battery Corrosion
Once you establish that the battery is the cause of the transmission problems you can fix it easily and fairly cheaply. A good battery service that includes cleaning the terminal ends should fix the problem completely. But if the connections seem faulty, it may be necessary to replace the terminals or cables. Either way, you will be back on the road in no time.
Can you do it yourself?
While cleaning the terminals and/or replacing the terminals or cables is a rather straightforward task, it is best that you take your car to a professional for two key reasons.
First, disconnecting the car battery will wipe off all the memories in your car’s computer systems. This will cause all kinds of drivability problems as the car systems relearn their bearings.
Second, disconnecting the battery could also disable a radio with a theft deterrent system until you input the theft code. If you don’t have the code, the radio will have to be sent to the manufacturer to reset it.
Many shops use a memory saver before disconnecting the battery. This device applies a low voltage to the system so the memories are not erased when you disconnect the battery. If you’re experiencing transmission problems caused by your battery, it is best that you let the professionals at Pro-Tech Transmissions handle all the servicing work.