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 limp mode code and a solenoid B code. I changed the solenoid and I’m still getting the solenoid B code. My fluid is clean. Can anyone give any advice to why I’m still in limp and getting solenoid B code. Vehicle type is a gmc diorama with an Allison transmission
2002 pt cruiser stuck in limp mode…p0700 code thrown from self scan…took to local mechanic…p0700 code thrown for him as well…scared to drive car further than 2 miles…the closest tranny shop is close to 10 miles….have been told multiple opinions from change the fluid to get a new trans…been told it’s the transmission control module to the transmission control solenoid….please help…can I risk driving the car to a specialty shop to have the specific scan done on the trans to determine what the p0700 code is saying? And what is that scan called that I need to have done? What type of scan machine is used?
2001 Saturn SL1 186000 miles had bad solenoid symptoms of slam shifting causing check engine light to come on then reboot a few starts later. Bought 5 used solenoids and contact plate on eBay ($90.00). Mechanic installed them ($150.00). Fixed problem shifts like new.
I just had two solenoids replaced on my 2000 Chevy Suburban. As I drove off, it seemed to not want to go, and then on the freeway would not go past what i believe to be 3rd gear. I drove right back to the guy, and he said we need to scan it because it’s still reading the old solenoid. I am wondering if anyone knows if that will actually help. To me it doesn’t make much sense, but I’m not mechanically inclined at all, so I may be way off. Any advice is appreciated, thanks!
Tiffany
If you have not done already go pull your neg. Battery cable off and put backk on and then try and see if that solves the problem. By pulling the cable it will put the codes back to default. Good luck..
Trouble codes found: P083B, P0944, P0733
2012 Dodge Grand Caravan CVP (Canada Value Package)
3.6L Penastar Engine with 145 000km
I first noticed problems at a red light –thought someone had rear ended me due to “bumping forward sensation when in drive” to realize nobody was near my back end of van.
Then noticed when driving was making whining noise -similar to that of power steering pump with low fluid.
Pulled over on road and tested. When in drive with brake engaged the rpm’s would rev up to around 1100 on their own. If I touched the gas to move forward the van would not engage the transmission until about 1500 rpm and then would lunge forward.
When shifter in park rpms would rev up to around 1100 on their own.
Anyone have similar issues/solutions etc? Van in shop now…
Thanks
Had the solenoids changed in my transmission for my Dodge Dakota 4×4 sport but the overdrive clicks on and off and the engine light keeps coming on any suggestions what it might be
My transmission started jerking at 35 miles per hour like going over speed bumps because the torque converter was locking up because of the solenoids. Replaced both and truck is fine 2005 Dodge Dakota 175000 miles serviced regularly oil and transmission.
2007 Nissan quest has a P0797 code error (Faulty pressure control solenoid valve ‘C’) stuck in open position. Does anyone know if this solenoid is a single part (lot cheaper) or does the 2007 Quest have the more expensive multiple unit pack?
Thank you.
I have ford focus 2008 2nd gear is delay shifting and 4th gear not shifting I have taken the car to shop and computer scan showed code P0732-ff ( transmission gear 2 incorrect ratio) ,(p0767-ff shift selnoide #4 stuck on ), p0981ff (shift selonide d control circuit) shift selnoide replaced and the problem still the same.
Please advise how to solve the problem.
thanks
Well i know this wont sound possible but perhaps your TCM has an issue.If the pcm is indicating that the trans has wrong second gear ratio perhaps the tcm has lost its( engine and trans model spcific) flashed in program and reverted to its base operating condition. A trans shop may or may not have a code reader to acces the tcm. I know autozone doesnt have one in the store. A ford technician with his laptop probbly have you straightened out in 30 minutes if it was a programing problem. If he is willing to do his job
Hi, I have a 2008 Cadillac cts with the 6L50 transmission which is giving an intermitten Slipping problem. Most of the time it’s fine though.
The slipping happens mostly…
If car is cold; hard acceleration from between 60 to 90Kph; after I’ve made a left turn and then going straight;
i notice… It never happens when accelerating from stop; or it’s down shifting. In manual mode it only happens shifting from 3rd to 4th and only once ever from 4th to 5th. Also it takes longer for the shift to actually happen after I’ve moved the gear selector going from 3rd to 4th. All the other shifts happen in approx 1 Second but the 3rd to 4th shift takes approx 2 to 3 seconds.
So far I’ve had the fluid and filter chaged 3 times, added anti slip fluid, had the 7 check balls changed in the valve body(tranny mech said one was too small), engine code p0391 cleared and never came back.
Any ideas anyone? A sticking solenoid perhaps?
I have a 2001 Honda civic automatic which had the engine light on for a couple months now but no shifting issues. Suddenly today as I was driving thru a parking garage uphill and my car suddenly is acting like its in neutral and wont drive or reverse. When I go to reverse or drive it just revs like its in neutral. Any help would be greatly appreciated.
Thanks in advance
1986 Nissan maxima automatic transmission. The is in park position, I move shifter into drive. The car don’t move but I put the select lever into the other positions reverse or the other drive positions and it moves on. What could be the problem? Everyone wants $1000.00 to rebuild it. I just want to replace the bad parts. Can’t afford that kind of money. I inherited the car from my sister that past away with cancer. My email is truckerbobg@gmail.com
Hi guys I have a 2004 Honda Civic lx automatic with 117k miles the car won’t shift properly the obd says solenoid b circuit low can any one tell me how much it will cost me to fix solenoid b for this civic thanks
I had a similar problem with my 2004 Jeep Grand Cherokee, where it would back up real slow in Reverse, and when I put it in Drive, it would take about 3 to 4 seconds before it actually went into gear, jerk forward, and then slowly pick up speed, after driving about 1/2 block. When I stopped at a stop light, it would sometimes vibrate, and shut off. I had to shift it to neutral or park, and start it back up. I replaced the Throttle Position Sensor, but that didn’t solve the problem. I finally gave in, and took it to the transmission shop, where I have had filter and fluid changes, and other work, done there before. The mechanic drove it, ran some diagnostic tests, and thought it was a solenoid pack that I needed. The cost of that, plus labor, would have run over $1,000; but when he dropped the transmission pan, he saw that one of the 2 filters, in there, had become loose, to the extent, that this was causing all of the problems. Replacement of this filter, transmission fluid, and labor, only came to a little over $200; much to my relief, and smile on my face. Even the Manager was surprised that a loose filter, was the source of the trouble, and that replacing it, solved the problem. Hope this can help someone else, with similar problems.
My 2006 Mazda tribute has been cutting off at the stop lights just like yours and the other day it was driving fine then all the sudden it would go in reverse but wouldn’t go I to drive then we let it sit all night and checked it out it would change over into reverse and DRIve then put it back in park and tried again it would change gears at all so we gonna check our filters and see if that’s it before we do anything else thanks for your info.
I recently bought a 4-speed B7XA Honda transmission in a 1998 Accord. The tranny was shifting heavily so I changed the fluid.
After the fluid change it was aok for about 100 km, then it started shifting down erratically from 4 to 3, slipping in 2 and sometimes refusing to change up from 2.
I removed shift solenoid C – the more accessible one – and tested its resistance as 20 Ohm, which is within spec of 12-25 Ohm. However, a second test, where 12V is placed across the terminals, resulted in what I think was a weak “click” compared to the sound which was made in a youTube video of the same test.
SO – and this is the question – I repeated the test under a nice microscope, watching the displacement of the solenoid’s internal shaft when voltage was applied. It was only 1mm. This seems low. The internal shaft gets pulled in only 1mm when 12V is applied. No-one has been able to tell me if this is adequate, including a Honda dealer. Would anyone here know and like to help? An experienced mechanic has told me that as long as it clicks, it is ok. True?
John < I did the same test on all my solenoids and found 4 of them to be weak. I'm not totally sure about car solenoids but in power plants if the solenoid has a weak click it is due to the windings wearing down and cannot produce the proper magnetic flux to pull the solenoid to its full potential. I suspect that the solenoid is going bad. But in automobiles they made have it, that only certain solenoids pull to their full potential and others to a lesser degree to maintain a certain amount of fluid pressure and or flow. Unless someone can come up with the answer to this mysterious question I am going to make plans to replace them–hold the old ones and see if things go well. Good luck
I know some idiot is going to say that that [this] “could never be the problem”, but, couldn’t it also be the Pressure Switch Manifold (part #24215111 in a 4l60E trans.)? >Of course it could.
I have a 2002 GMC envoy and the other night when I got home I put it in park and when I went shut it off to take out the key it said that I was in 3rd and won’t let me take the key out. I turn the car on and it says it’s in park, so I turned it off and it want back to third.. I did this several more time and it did the same thing. I took the remote off the key chain and lock the car and went inside. I came out 5 minute later and it finally released the key.. I am very confused.
I was driving my 2007 chevy silverado and the check engine light came on. put a scanner on it and there are 5 codes all dealing with transmission, solenoids and torque converter some say circut open and the truck is in park but scanner says 3rd gear. it has no power on take off and I need to push the gas pedal hard to get it to move. does any bojdy have any thoughts on do i need to replace the whole transmission or maybe just the solenoids, maybe a fuse that communicates to the PCM controller or any other Ideas on where to start. the fluild level is good and no burnt smell to it. Thank you in advance for any help with this.
There is a fuse located under the hood (drivers side) check the fuse before you do anything to your transmission. If it’s not the fuse, I would pay to get a diagnostic ran with a professional scanner. In other words take it to a mechanic and put a “High Speed” scanner on it, instead of a cheapo. Anytime your fluid looks nice and red, it’s always a good sign. Hope this helps.
My 2004 jeep cherokee sports gets stuck in first…wont shift to 2nd or third..or forth 8f 8t gas one..i was driving along..engine light came on..then it jumped back to first…it is ok around town..changes gears easy..engine light never goes off..please help..my mum just died and short on money..is this a solonoid problem..have had it on dyno but computer wont say whats wrong..cheers
Hi everyone, I have a 2007 Dodge Charger 2.7 liter 6 cylinder. I just bought it off this guy who had the car sitting for 2 years. Everything seemed to be good when I was driving it home for the first time, no problems shifting and whatnot. The next day when I drove it, it wouldn’t shift past 3rd gear. Of course this had to happen while I was on the freeway and I can only go about 30-40 miles an hour. I got off the freeway as quickly as possible and took side streets the rest of the way home. Good thing I wasn’t too far from home. I have a code reader and P0300, P030, and P0760 showed up. Someone said it can be really low on transmission fluid And there is no way of checking because on my car there is no transmission fluid dipstick…nice huh? However, there was a transmission plug at the top of my engine so I put a quart in it. I let it run for a while and it did start shifting again but guess what happened next…yep you guessed it, same problem happened again. Aahhhhhhh! So, the codes point to shift solenoid issues. Does anyone think it can just be old tranny fluid or what do you think? 🙂
I have a 2003 Audi A6 C5 automatic with TIP. While I was driving on the highway at 70, the car suddenly slipped in to a lower gear, I suspect 4th, and I immediately put it in neutral and coasted to a close exit. I shut the car off and turned it back on, it was in limp mode. I was able to get home, about 10 miles. Now the car has no reverse, and the TIP does not change the gears either, it will drive forward and once I hit about 30 mph or so, it slips in to limp mode. IN an attempt to fix this problem, A friend and I pulled the engine and trans, separated the trans from the engine to check the torque converter seal, it looked suspect so It was replaced. We also removed the pan, there were NO signs at all of material, metal, fibers, nothing in the pan or on the magnets, the fluid even looked reasonable No burnt smell. We put in a new filter, new pan gasket and put it all back together and back in the car. What a job! We went through the proper filling protocol with new trans fluid, using the proper fluid for the Audi trans. After all of this effort the symptoms remain the same. Could this be a value body issue? Thanks!