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?
My 2001 Chevy three quarter ton 6.0 keeps running hot when pulling a load changed transmission screen and fluid still runs hot got up to 240
I have a VW Passat B5 2000 V6 2.8LT
The transmission shift hard from 1 to 2 and after a while it gets stuck in 5 . Simultaneously the LCD panel highlights PRND4321.
On a page from Peru, a guy saids that’s the problem are the selenoids and that if you purchase the originals you will still have the problem. He said that the solution is a set of Selenoids manufactured by Rostra in USA.
Please advise.
My 2004 Chevy suburban starts and runs just fine works in reverse works in drive but the gearshift slips between first second third around 20 miles an hour 45 miles an hour and he refuses to jump in to overdrive at about 60 or 70 miles an hour oil pressure goes up at struggles to do 70s in at about 5000 RPMs
Pressure control solenoid
My 2003 trailblazer 4 wheel drive won’t shift into third gear
I have 2002 Chevy trailblazer it goes in reverse fine and it will shift from 1st to2nd but will not shift to 3rd and there is no codes to go by what wrong with it
Got a 96 cadalac DeVille put solenoids in the transmission put back together put trans fluid back in 4quarts I put in drive it will move but it want move in reverse
Not enough fluid or reverse band and sunshell band
95 Chevy c1500 Silverado 2wd automatic extended cab all forward gears are gone got reverse
No reverse
Sunshell broken
2005 impala go’s forward in 1st gear but not in drive you can’t feel it go in gear when you shift it into drive
It leaks supposedly from solenoid pack
I have a 2012 dodge caliber sxt 2.0
I have a code p0777. Had it diagnosed and was told that it slips in 3rd and 4th gear and down shifts in 4th gear. Once it’s warmed up when I go to start from a stop it does nothing as if it’s in neutral but the rpm does not change.
Will changing the valve body fix this problem???
Any advice would be great
Shift solenoid pack
the focus was shifting hard into drive, got an error code and the little orange wrench, diagnosed bad C shift selenoid, so i replaced the selenoid with a new one, an also replaced the A and B shift selenoids while i was at it. when i was finished, i have no forward drive, i still have reverse an nuetral, but no GO, why
Car won’t shift into 2nd gear or reverse. When the car heats up, is when I notice the problem, car has no power. I replaced 4 out of 5 of the shift Solenoids for my 99 Saturn SL2 . I am on limited income and don’t know if it is the entire transmission or the 5th solenoid?
It won’t shift,and did code diagnostic and it came up PO 449 SELENOID
I have a 2010 Jeep liberty 4×4 and shift solenoid A went out and it was stuck in 2nd gear so I replaced it still stuck in 2nd I need some suggestions
Can transmission shift solenoid cause your car to fail smog? 2000 Toyota Avalon. In California of course.
2016 ford fusion SE 2.0l turbo trans is randomly hard shifting and slipping.
for a while i only got code P0219 and P0731, p0732 inconsistently. latest code i got was P0751 and P2700. this 6F35 trans doesn’t give up codes easily. it sometimes wont give me any codes even when something is obviously wrong with it. Had to drive it for 3 weeks while it was acting up to finally get more helpful codes.
It will shift into gears when the tranny is cold.once its warmed up you can shift it into gear but wont move.or if i shut it off and wait then restart it .it will go into gear and move for a very short period then loses torque and wont move
Mine did that as well. It’s currently been in the shop for two weeks. They are telling me it’s the solenoid actuator. I’m scared to find out what the final price is going to be when I get it back.
what was replaced and what was the parts and labor break down cost
I’m having the same problem as jhon the truck will shift intill it gets hot then won’t pull till it cools it will go for short distance what can you tell me about it
I have a 20003 cts .i was driving all was fine came to a stop. Went to take off and nothing happened it acts like in neutral for all gears .itvdoes make a noise in park like it is not fully in park .
I have a 2008 Subaru Outback. It will periodically shift hard going into 1st or 2nd gear. When this happens the check engine light comes on and the cruise control light flashes on and off. They will turn off and on their own in a day or two. Took it to transmission repair shop and they flushed tranny, …. still has the same problem. Took it to three other mechanics and as told by the last on(Hartnell Transmission) that it’s a mystery and to drive it until it won’t. Was told by a friend that it sounds like a shift solenoid. Took my car in for oil change yesterday, explained to that mechanic what was going on and he said it sounds like a shift solenoid.
I have a 2008 Subaru Outback. It will periodically shift hard. When this happens the cruise control light flashes and the check engine light comes on. They will both turn off after a day or couple of days.
My 2003 Buick Rendezvous had similar. Sometimes it wouldn’t go in D so I dropped it down to 1 or 2 and then it would go at which point I then went to D just fine. This didn’t seem hard on my transmission at all. In colder weather I had to let engine warm a bit before putting it I to D. Soon as I could I had my transmission serviced and it quit doing it altogether. Been fine since but a few months ago I started having a bit of a misfire intermittently as I was getting on freeway at about 40-60, but then it wouldn’t happen for awhile. I knew I needed maintenance tune up and had just been told that the guy who’d last changed my spark plugs hadn’t been able to reach one, so it had been a couple years since then. (I don’t drive a great deal.) Intermittent misfire got a but more frequent. At one point the “service engine soon” light came on but went out again. So I made an appt with a repair shop and took it in at the beginning of this month. Told them what was happening so they said $70 got diagnosis and then later said they came up with the solution to be replacing spark plugs and wires. Price was still quite good since I’d been quoted $100 more. So, picked it up and drove home perfectly. An hour later I went to get gas but it took a long time waiting in line for gas. When I pulled away from pumps it died on me just down the road. Got it started again and it would jerk and die again. Managed to get
Back home going very slow cuz accelerating would cause it to die. Took it back to shop and they said it needed a new oil pressure switch, so another $175. It died 3 or 4 times on my way home. Now it sits in the driveway as I am broke for the rest of the month. I will have to tow it back in on my payday and see what else can be wrong. It’s had an oil leak for a long time, but there are a lot of things that need worked on. So anyone with any hard shifts or misfires need to get things checked out asap before major repairs are needed.