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 2008 f 150 kingranch. i had to have the transmission rebuilt about 2000 miles ago. since i got it back a few times a week when shifting from 1st to 2nd it slams really hard. the shop says nothing is wrong with it and cant find anything wrong with it when they drive it. I asked about the solenoid, if that could be why its doing the hard shift. they put the same solenoids and valve body in it when they rebuilt it. should i change them or what else could i do?
Don’t let them get away with that crap. If you paid them to a job, and they didn’t do it right, it is their responsibility to make it right, since you already paid them. Don’t take any excuses from them, and make sure they know that you know how to call a lawyer.
I just picked up a 2003 monte carlo ss, transmission would not shift from first to second gear would only shift from first to second if you let foot off accelerator. after doin a little research I decided to replace shift solenoids and pressure control solenoid. once I got done and took for test ride now I have no first gear. I just took it all a part again and I found third -fourth solenoid not plugged in all the way. could that be my current issue even though it was third – fourth solenoid and not first – second or is it just a coensidence
My 2008 Chevrolet Silverado will not go into reverse. And when the shifter is in neutral it still goes forward. It goes fine forward but reverse is something else. Does anybody have any idea what could be the problem. I am a disabled veteran so I need my vehicle.
I have a 2009 Chevy Cobalt (automatic). I drove approx. 150 miles from home, did not have any problems out of the transmission.. yesterday morning I woke up and tried taking my grandmother in law to the bank. The car went into reverse just fine but then when I put it in drive, it would not come out of first gear…. if I try to press it to shift into second all it does is rev… I took it to autozone where they put it onto the computer and it didn’t come back as anything wrong… please help… I have never had any problems out of this car before.
i have a 92 geo tracker auto tranny it shifts fine in1,2,and 3rd but doesn,t want to shift in over drive once in awhile it will now the motor is starting to smoke due to the tranny not shifting in 4th gear. what could it b i changed fluid and filter still the same
Hi. I am looking for shift solenoid for a 2007 Mini Cooper. Where is the best place to purchase. Called a dealer and the sales person didn’t even know what I was talking about. Help.
I have a 2008 Ford Escape that when I’m accelerating usual between second and third gear the RPMs will race to about 4500 before it eventually change into the next gear and It’ll be fine. I was wondering if that sounds like a solenoid problem or something more
I have a 2007 Mini Cooper. The engine light came on so I had it scan which show the solenoid shift. The car took me home over 40 miles and ran well all the way home. My question is I will have to take it back about 50 miles for the repair. Will it go that far without further damage.
hello jacob
i do experience some kind of misfire-like symptoms in my 2006 corolla. and recently engine light came on. i check the code it was p0741. this sometimes happen around 45mph- 50mph , should be in my 3-4 gear. what could be the cause? thanks
Hi Everybody,
I have Holden Caprice 2008 V6. it was working well sometime in speed 60 to 70 km its feel car has knocking same like we put 5th gear in 3rd gear speed. then when you stopped pushing accelator, its neutral with some abnormal behavior. then its stuck to 3rd gear even in D mode. when i checked it with OBD Scanner it said P0974 shift solenoid A control Circuit High. I change the fluid it was low. I complete flushed it and refilled it with recommended fluid and level. but it still the same. Also when I push lever from P to R, R to N, N to D or D to N, R,P. car moves a little Fwd And Back
If the scanner says the solenoid is bad then change it. That’s the point of the codes. If your worried about replacing something not broken then just take the part with you to the part store and have them check the resistance for you. If you don’t know exactly which one it is just go to the dealership and have them look it up for you. They will even print you out a diagram. Simple procedure in almost all cases.
i have a 1999 s10 zr2 4×4 with the stupid 4l60e trans. Trans was working fine fluids look and smell fine. Got stuck in the mud the other day and the next day started acting weird. It woudnt go into reverse. Shut the truck off, start it up and walla goes into reverse. Next it started slipping in and out of gears. Now, it only moves when its cold. It has all the gears, shifts great, soon as it warms up(maybe a mile or so) nothing. just revs up and goes no where. Let it set for a little bit, repeat. Any ideas?? selonoids,modules, or just shot thx
You have a line going from your trans to the bottom of your radiator. The fluid travels through there circulating and being cooled. If this process is interrupted you fluid won’t circulate it just remains in the transmission getting hot and starts to burn from the friction. Once it gets hot your clutches start to slip and wear down. Check your fluid line and make sure you didn’t damage the bottom of the radiator. Its very sensitive. If you did then you can always buy an external fluid cooler instead of having to buy a whole new radiator. But first make sure you didn’t pinch off the line somewhere. It will also shift weird when it is cold because your building up too much pressure which is how your transmission knows to shift.
I have a 02 Dodge 1500 with similar problems. The MIL code is P0845 transmission fluid pressure sensor circuit b switch. The truck will abruptly kick out of overdrive at which point I lose 1st gear and overdrive and have to shift from 2nd to 3rd manually and vice versa. I read on several forums that this is the solenoid/solenoid pack. I need to know which solenoid I need to buy/order to replace in order to fix this problem.
Check the sensor that kicked the code first. The transmission fluid pressure sensor or switch. Take it to the part store and have them test it for you. Your local dealer can help you locate it but with YouTube and Google you should be able to find it yourself.
please help! my automatic container capping machine does upshift or downshift. what could be the problem?
2000 Hyundai accent does reverse,what should I do
I have a Nissan Sunny B13-1991 Automatic transmission. Cold or hot all forward gears work the reverse only works after the engine warms up then reverse works perfectly until engine is cold. I am using Pennzoil synthetic Multi vehicle ATF.
What cab be causing this problem I would appreciate your comments
I have a question about 3-2 down shift solenoid on my 2003 Chevy Blazer 4.3L 4×4 with 4L60E 1GNDT13X33K118521 transmission tag 3TAD 613TADY33958673 24217273
IF someone had changed the (3-2 downshift solenoid) measuring 20-31 ohms with the older 10-15 ohms one OR the other way around what would it do to the transmission? I have the 2003 up style EPC (which I can’t find an ohm specification ANYWHERE for the newer EPC). I think this trans may has been opened and rebuilt before and I am not sure they have the correct 3-2 solenoid installed. How do I find out? Thanks for any input.
Call your local dealer and give him the vin number of the vehicle and the number from the trans. He’ll tell you if your matched up right and which solenoid belongs in there.
I have a 05 Chevy Avalanche z71 4wd had a service 4wd code had master encoder replaced end will not shift into overdrive but is not giving any codes? did not have this problem until service 4wd code started flashing
I have a 96 jeep cherokee 4.0. I broke a front u joint but had to drive another 8 or 9 miles home. Fixed the u joint now my jeep will go in reverse but I shift to drive and it revs and pulls slow won’t shift up. However I can mannually shift 1st to 2nd 3rd and overdrive. What is the problem
It is not shown in the workshop manual^
HI i have come up with an issue with my B solenoid (3-5-reverse clutch), just wondering how to identify the individual solenoids. they are in an assembly of 7 solenoids in a 2010 holden epica(australian car), same as a chevy tosca, need to identify and replace the B solenoid, but not sure which one it is.
thanks
Chris
none of the problems help me with mine. I have a 2005 pontiac grand prix 3800 i was having overheating replaced the water pump, thermostat, the little elbows, my tranny has been fine no jerking no irratic behavior i drove it yesterday it went fine over heated alot which was unusual i go to go to work this morning shift into reverse it goes in the street then shift into drive nothing go back to reverse nothing. i go out to let the car warm up and the damn thing stays on 1/4 warm up blowing nice heat but still wont shift could it be a sensor? dont see it being tranny as it was working fine please help