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.
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Does the tcs and the abs have something to do with the brake siystem
location of shift seleniod on a f150 v6 1999 pu transmission
My 97 Ford ranger 5 speed was stuck in 4th I did a shifter repairkit and transmission fluid change and now it wont shift out of neutral
Having major issues with PT cruiser. It’s goes into limpmode after the engine has warmed up and after I switch off the car and turn it back on again to drive somewhere. I though it was a bad tipm and PCM don’t know for sure. Now I’m discovering a transmission solenoid maybe at fault or something. Tipm and PCM may be bad but mehanic might be lying don’t know for sure.
Exactly the same thing with my 2002 Dodge Neon. After 8 miles of driving it goes into 2nd gear and won’t get out. Hope you find a cheap solution that you can share. My Neon isn’t worth the cost to fix.
I have a 2004 Vitz 1.3cc 2sz engine car… it’s gear is not shifting properly and check engine light is on while driving up hill
Buick lesabre hard down shift, Waths the problem?
Have a 2001 toyora sienna v6 everything is gpod except no reverse all foward gears good
I have a 1999 toyota camery with the same problem.
I’m having issues with my automatic Ford 2006 won’t move when gears are in drive and reverse an the transmission fluid is fine
Likely the torque converter, not the transmission?
very good read.! the more we know the less money we have to pay so read up ppl.! dont just go by what your mechanic is telling you. do your research on your own ask for the codes and look them up.
I have a 2004 Ford freestar
Is it the same cost to change the solenoids in that van
Have a 2010 Mazda 3 and when you put it in reverse it lunges back fast ,,don’t know engine size but you can also use auto or shift 1st 2nd 3rd gear, any help would be apreacitive
I was about to purchase a 1996 Mustang V6. It goes into reverse easily, but has trouble getting into drive. It’s an automatic.
I have a 2006 Impala was sitting at the red light and drive and went to take off easily and I felt something give now I am driving it but I have to manually shift though very weak low gear second once it gets in gear it strong 3rd it strong drive it strong but car will not take off in any gear but low how do I know what solenoid it is or if it’s even a solenoid
It’s probably a solenoid pack , so all of the solenoid get replaced at once , mind was in the pan on the valve body that the filter is attached to, you need to disconnect the shift lever, and disconnect the speed control and turn the shaft all the way clockwise or in low 1 before you drop the valve body there are like 13 10mm bolts that attached mine inside the transmission about the pan and like 4 torx head bolts holding it on.. and change the fluid..it probably a 4 hour job or so. It probably is the solenoid that control on of the gears mine had 4 because it’s a 4 speed. Good luck..I guess if your fluid looks okay.. like dirty with normal friction material from the clutches..if you have metal shavings or hear grinding you probably have bigger problems, but sounds like your solenoid pack.
Now it won’t shift at all
Hey I have a 97 Ford Ranger XLT excited cab automatic it was shifting into 1 and second but made like a clunking noise and hard to stuff what’s solenoid do I need and how to replace it
Where is Pressure solenoid A for 2004 honda pilot location
Where is Pressure solenoid A for 2004 honda pilot location
2002 f150 5.4.4×4 Slips between neutral and first.
What was cause
I have a 2000 Lincoln mercury mountaineer. The check engine light has been intermittent for a while. Now the O/D light is blinking. Brought to my mechanic who changed the fluids and did other things. He says to baby it while driving. everything was fine for a few days, now the O/D light is blinking again. What should I do. Chuck the car for a new one? I’m not ready for a new car now. I don’t think the car is worth the cost of a new transmission.
Hi,yesterday I changed a flat tyre,all sorted,jumped in to start her up,nothing,I noticed the gear selection was on 2,flashing,I have no gears at all,nothing,I read a few reviews regarding this problem,don’t know whether to fix it or just flog it off to a car wreckers,..
Needs to be trouble shooted to pinpoint the problem,and then get a price on parts and labor.40yrs exp.
I have a error code P0722 on my chevy cruze Output speed sensor circuit no signal. The car is able to start but when u shift the gear it moves at the low gear but does not change to upper or lower. Reverse works fine. My concern is this due to problem with the output sensor since there is 2 sensor which is output n input sensor. To replace this can we do it without removing the transmission. Could it selonied problem. Need advice wht to change and check.