Transmission Solenoid: Symptoms and Replacement Cost

Transmission Solenoid: Symptoms and Replacement Cost

It is not a secret for an automatic transmission owner that gears are changed thanks to a pressurized hydraulic fluid. When comes the time to change the gear car’s computer engages the solenoid, as a result, the fluid is injected into the valves to activate the proper gear. If there is a problem with one of the valves, you won’t guess what kind of problem you will have in future. So, it is better to be more aware of the solenoid shift and troubles you may come across.

Below you will find out what are the symptoms and the cost of TS replacement.

How does a transmission solenoid work?

While you are driving a car, your computer analyses information gathered from car’s speed sensor and from the sensor that measures the engine speed and power. After the analysis, the Transmission Control Unit or the Engine Unit determines the most comfortable shift and sending the message to one of the solenoids.

The solenoid has a spring plunger inside with a wire wrapping, so he is getting activated by sending an electrical charge by ECU, after activating the solenoid, plunger allows the fluid to be injected in the valve to switch bands and clutches. This process is done every time when your car changes the gear.

If the car has a special dedicated TCU it can control the hydraulic system with a direct signal of 12 V. Otherwise, the ECU may control the plunger in the solenoid by switching the ground circuit. The solenoid can control not only one gear but several gears at ones, that depends on the model and its complexity.

Here is a comparison table of prices on TF and change service:

Transmission Flush vs. Change | Cost
Flush$125 to $250
Change (Shop)$80 to $150
Change (DIY)$40 to $90

Symptoms of a transmission solenoid problem

Here is the list of the most common problems:

Transmission won’t downshift – If it is impossible to downshift that means that solenoid is stuck, the fluid cannot fill the valves and the power gets low. Under such circumstances, it is impossible to gain the pressure to shift the gear.

Erratic Shifting – if there is a problem with a solenoid, the gear box may skip and shift up and down repeatedly or, what is worse, stuck.

Severe shifting delay – the fluid pressure makes it available for the computer to shift gears in an appropriate way. If the wire wrapping on the plumber gets too little or too much electric current or the transmission is dirty so that caused to the solenoid stuck, gear changing may become difficult or unstable. It may look like having the transmission in the neutral position.

Thanks to ECU all solenoids are connected to the system and if something goes wrong you will be informed. Usually, the error code appears and you must be sure that engine needs a diagnostic service. The computer may block the transmission box either limit it up to the 3d shift not to allow you to reach the high speed.

Transmission solenoid replacement cost – parts and labor

Depending on the type of transmission, a solenoid is often placed inside of the pan with oil connected to the valve body. The whole replacement is done in 2-4 hours, the shop time is valued at 60-100$ per hour. So, in total, a replacement will cost from 150 up to 400$.

Single transmission solenoid replacement will cost 15-100$, while a total (pack) replacement cost can be 50-300$.

TS Replacement TypeReplacement Cost
Single$15 to $100
Pack$50 to $300
Labor$120 to $400
Total (Pack)$250 to $600