Without a valid speed signal from these sensors, the PCM will not be able to correctly control the shifting of gears within the transmission. It’s also common that a problem with these sensors can impact the shift timing, extending the interval between transmission shifts.

The output speed sensor measures how fast a vehicle moves and sends that information to other vehicle systems. The transmission control unit uses the speed to determine when to change gears, adjust the torque converter and display the vehicle’s speed in the speedometer.

Therefore, a failing speed sensor will have a direct impact on automatic transmission operation. One of the most common signs of a bad speed sensor is abnormal automatic transmission operation. If the VSS is faulty, the transmission may exhibit symptoms such as delayed shifts, hard shifts, and limited gear operation.

1. Transmission revs higher before it changes gears.
2. The car’s transmission engages into overdrive late and sometimes will never go into that top gear.
3. Brakes are sometimes harder than normal when coasting.
4. Speedometer behaves erratically or sometimes does not work at all.

If you’re experiencing transmission solenoid troubles, it will become evident in one of four ways:

1. Delayed gear shifting.
2. You can’t downshift, and your engine continues to rev even when applying the brakes.
3. Your transmission gets stuck in neutral.
4. Shifting gears become rough and choppy.

A problem with one or more of the solenoids can cause a lack of pressure, resulting in hard, soft or delayed shifts. A failed shift solenoid can also cause transmission slippage, where your engine revs faster but the car stays at the same speed.