Modern automatic transmissions use pressurized hydraulic fluid to change gears. Every time a gear change is required, the car’s computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the correct gear. If one of these electro-mechanical valves fail, then all sorts of transmission problems can ensue. So let’s take a closer look at the shift solenoid, and the common problems associated with it.
What Transmission Do I Have?
How Does a Transmission Solenoid Work?
As you’re going down the road, the car’s computer analyzes data being sent by vehicle speed sensors and engine speed sensors. Based on this information, the Engine Control Unit (ECU), or the Transmission Control Unit (TCM), executes the appropriate upshift / downshift by sending a signal to one of several shift solenoids. These transmission solenoids have a spring-loaded plunger inside, which are wrapped with wire. When this coil of wire receives an electrical charge from the TCM / ECU, it causes the plunger to open, allowing transmission fluid to flow into the valve body and pressurize the desired clutches and bands. When this happens, the transmission changes gears and you continue down the road.
The car’s computer can control the transmission solenoid in several ways. If the vehicle is equipped with a dedicated Transmission Control Unit, it can open or close the hydraulic circuit using a direct 12v signal. Or, the Engine Control Unit can control the solenoid’s plunger by turning the ground circuit on and off. A solenoid can be used to control a single gear or multiple gears, depending upon the complexity of the design.
Symptoms of a Transmission Solenoid Problem
A transmission solenoid can fail due to electrical issues, or dirty fluid that’s caused the shift solenoid to become stuck open / closed. Any change in the transmission fluid pressure can cause numerous problems, including:
Erratic Shifting – If you’re dealing with a failed transmission solenoid, the gearbox can skip a gear up or down, shift back and forth between gears repeatedly, or get stuck in a gear and refuse to shift.
Transmission Won’t Downshift – If the transmission will not downshift, one of the shift solenoids may have become stuck open / closed, preventing fluid from entering the transmission valve body to pressurize the correct gear.
Severe Shifting Delay / Stuck in Neutral – In order for an electronically controlled automatic transmission to shift gears, the solenoid must be able to regulate the fluid pressure to activate the appropriate gear. If the shift solenoid is receiving too much or too little electric current, or dirty transmission fluid has caused it to become stuck open / closed, gear engagement maybe become difficult or delayed, which can cause the transmission to act as if it is temporarily locked in neutral.
Because the solenoids are connected to a vehicle’s electrical system, the ECU will usually register an error code and trigger the check engine light if something goes wrong. If this happens, the transmission can go into limp / fail mode, where it will only engage second / third gear to limit the vehicle speed without immobilizing it.
The first thing that your mechanic should look at are the error codes. Using a scan tool, the technician can determine the source of the solenoid’s problem. It could be as simple as a bad ground, or as complex as a failed solenoid pack (a grouping of individual shift solenoids).
Transmission Solenoid Replacement Cost – Parts & Labor
In most cases, solenoids are located inside of the oil pan, connected to the valve body. Depending on what you drive, the technician may be able to replace just the failed shift solenoid. However in some cases, the solenoids come in these multiple unit packs so if there is a problem with one, the entire pack must be replaced. This job typically takes 2-4 hours to complete, and shop time is generally billed at $60 – $100 per hour. The average total cost to diagnose and replace one ranges between $150 and $400.
Depending on the make and model of your vehicle, expect to pay between $15 – $100 for a single transmission shift solenoid. A pack can cost $50 to $300.
| Type | Cost Range |
|---|---|
| Single | $15 to $100 |
| Pack | $50 to $300 |
| Labor | $120 to $400 |
| Total (Pack) | $250 to $600 |
Although it isn’t unusual for transmission shift solenoids to wear out over time, you can extend their life by changing your transmission fluid at the factory recommended intervals. This will clean out all of the dirt and sludge that builds up, and the fresh fluid will keep the plungers on the inside of the solenoids from sticking. If you don’t know what your vehicle’s recommended transmission service intervals are, check the back of your owner’s manual, or simply ask Google.
Get a great deal on a replacement solenoid – for as low as $11 on Amazon <
Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.
What Transmission Do I Have?
I have a 2017 honda civic hatch sport , daughter decided to do a burn out and now it’s locked out of first gear grinds second but the rest shift fine . Some say transmission others say solenoid in the transmission
shifting issues, 2012 Ford Focus SE, missed the class action lawsuit
I have 97 dakota.the transmission has only 2 gear and sometimes 1 gear
When car is cold it won’t move when put into gear
09 f-150 hard 3-2 downshift
Hard 3-2 downshift
Ok so I have an 03 Taurus, just recently it started Not wanting to shift properly.. that is it started shifting hard from 2nd to 3rd or to 2nd from 1st.. now it shifts into 3rd when it feels like it or if I help it along the way by dropping it to low drive or 1 and ease it back up to D drive. My honey says it’s a silinoid and I say it’s the torque converter.
Mind u reverse works great & it ran like a champ prior to this lil shifting issue. And there is torque when you start from 0 to it needs to shift to 3rd.
Yes I have a BMW 328i 2007 and I’m having trouble with the transmission if it’s in Drive and I take off it shifts all right but it shifts real fast but if I shift into sport mode and take off it stays in second for a long time before it shifts or I have to let off the gas and then it will shift
Car will not shift into any gear. Like it’s not getting gas. 2013 mitsubishi outlander sport. Well taken care of.
I have a ’16 impala ,trans clunk going to 2nd gear and clunk when downshifting
Code PO83B transmission solenoid switch cost to fix
Only when cold and upon putting the trans in drive, when I come to a full stop I lose 1st gear or feels like it’s in neutral. When that happens I select reverse then drive and I get 1st gear back again. After about a min. or so during warm up the problem goes away and all is normal. About a year ago this trans. got contaminated with coolant because of a failed transmission cooler in the radiator. The cooler was replaced and the transmission fluid was changed three times in order to remove as much coolant as possible. Since then the transmission has worked fine until recently I had to replace a output speed sensor. After replacing the sensor the trans was fine until about a month or so when this current problem started. The vehicle is a 08 Acura rl with 210k miles .
MY BACK WINDSHIELD WAS SHATTERED AND I TAPED AROUND THE WATER EXIT MAKING IT TO DRAIN MY TRUNK WETTING MY BATTERY SINCE IT’S A BMW 2012 740LI I was getting pulled over by the cops and had to turn it off on D which got it stuck with a blinking flashing D I’m not sure what to do I can’t afford a mechanic I’m pregnant single mother of 3 boys please help any clue that you have will be appreciated thank you so much
Sorry I have a 2005 trailblazer 2.4 6cyl 4wd.
I rebuild tranmion it’s not pumeing flued it seem like it’s not doing anything like it did before I dont have current on fuse 111 I do on 31 they say it for transmission
Have a 2003 Ford Focus SE, 2.0 Engine, Had a bad shifting cylinoid B, I had both A& B replaced, my car is still doing same as before, and the diagnostic tool says it’s still shift cylinoid B??? DOES MY TRANSMISSION OR SOMETHING NEED TO BE REPROGRAMMED?
46re changed solenoid, transducer, changed pcm old one works fine, did a connectivity on the 5 wires to pcm(all good), runs for 2-3 miles(when it gets hot) it dies, No Bus, P0920, P0921 P0999. 5 mins to hour runs again. don’t know if I’m dealing with an electric problem in wiring or mechanical problem with high fluid temp, bad transducer, or solenoid. switched to synthetic fluid.
Idles fine. Put any gear it dies
I have a rebuilt 04 trailblazer 4l60 transmission. Now line pressure blows a cooling off and will not go into any gear. Any suggestions
I have a 1999 Ford explorer which doesn’t engage in reverse neutral drive overdrive second number it’s just like it’s in neutral at all times what is it that I must do to provide the adequate function to my transmission
2010 Dodge Dakota Transmission does not shift. No slipping. Will go in reverse. A little winning. Light came on. Have not run since light came on.