WHAT THE HECK IS A…Shift Solenoid?

To know what the heck a shift solenoid IS, we must first explore what the heck a shift solenoid IS NOT. A shift solenoid is not:

  1. A video game minion robot character
  2. The program that assigns work schedules
  3. A candy made by Willy Wonka
  4. The device in a keyboard that enables capitalization

I’d play that game.

So…what the heck is it then?

A shift solenoid is a computer controlled, electronically activated component of an automatic transmission system. There are multiple shift solenoids in a transmission. They are responsible to open/close certain valves in the transmission to regulate the flow of the transmission fluid, which causes the transmission to actually shift gears.

How Does It Work?

Shift solenoids have a spring loaded plunger wrapped with a coil of wire. Through the wire, the plunger communicates with either the engine sensors or the transmission control module (TCM—which is not Turner Classic Movies) via electronic signals. Those engine sensors determine when it’s time to shift gears based on speed.

When the shift solenoid is activated, the plunger will open certain valves in the valve body to allow transmission fluid to enter. That puts pressure on the clutches and bands that cause the transmission to actually shift gears. When the shift solenoid is not given any power, the plunger will close.

Failure

There are a few things that may indicate a problem with a shift solenoid:

  • Delay in shifting gears, during which the vehicle won’t be able to accelerate
  • Transmission doesn’t shift into lower gears or does it randomly
  • Transmission shifts into the wrong gear, skips a gear, or shifts back and forth randomly

Since it’s electronically activated, an electrical malfunction could very possibly be the cause of any of those issues. If the check engine light comes on, you can bring your vehicle to your local trusted mechanic to scan the fault code, diagnose, and repair it.

If the check engine light doesn’t come on but you are experiencing shifting problems, the problem is most likely a mechanical issue, and you can bring your vehicle to your local trusted mechanic to verify and replace it.

Either way, if you’re experiencing any of the above issues, you can (read: SHOULD) bring your vehicle to your local trusted mechanic.

This little guy waited until it was too late. Now his very expensive Rolls Royce needs a new automatic transmission.

 

So, there you have it. Now you know what the heck a shift solenoid is NOT, what it IS, and learned what signs should alert you to bring your vehicle to your local trusted mechanic–unlike that poor little baby.

 

Tell me what other automotive parts baffle you. I’ll tell you what the heck they are!

Written by Ben Scharff

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