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 changed out the transmissions on my 2008 ford escape fwd, 2.3 liter engine. Now the vehicle will not start. Will not even crank, no noise at all. You can start it at the starter by jumping it off. After starting vehicle would not move. Every gear was like it was in neutral. No problems before changing transmissions. The old one had a broke bad
2011 equinox slipping in high gear and reverse. Can it be a solenoid? And my mechanic said there were no codes
2010 VW routan I need to replace the gear shift solenoid code number p075a where is it located and how difficult to replace
My transmission in 05jeep wk shifts fine but will not shift manually up or down.what is the problem
Trans # is 6T70
I have a 2013 Buick Lacrosse 3.6l i/6 spd trans, while traveling on the hwy my trans light came on , saying transmission fliud is Hot idle engine.spd at the time was 70miles per hr , I have 170, 300 miles on this car, is it worth the repair cost.
My shift solenoid B on 01 RAV4 needs replacing and all shops are saying to replace all transmission? I have the ignition coil already but am I being told wrong? My rpms shoot up and down and misfires.
my 2009 mitsubishi lancer gave me a p0746 code for transmission solenoid A stuck off i was wondering if you know where is it located?? thank you and please give me an answer ASAP.
I was told that my shift solenoids were bad the rpms shoot up when I am driving.
My 2010 chevy HHR is doing the same thing
I was told all I I can clean the solenoids is this correct so
How do you do that ?
Truck shifts fine. Only problem is no reverse lights. 2003 Dodge Ram
What ended up being the issue? My gmc terrains doing the same.
Basic high level overall explanation that is pretty good.
2006 Mitsubishi Eclipse got down shifts and green light flashes on when driving down the highway and it shifts into gear hard at times when I shift to drive from park
When a car goes in reverse gear but not in drive , is it a symptom of bad solenoid.
The drive engages after having accelerated for some 20 secs or more.
Problem only occur on cold engine start.
Notice oil leak on transmission shaft oil seal region.
How do you access the shift solenoid in a Lincoln mkz?
light is on in my 2003 honda odyssey and when I get to 55 and let all the way off the gas it whines real loud like I put it in neutral the transmission shifts fine
I need to know where the 1st and 2nd gear solenoid is located on 01 crv awd
I have a 2.7l dodge magnum with shift solenoid A and B out can I just replace the two solenoids instead of the solenoid pack
Chevy cruze 1.4 auto tops out at 90mph???
Sounds funny and runs hot. Poor gas mileage.. Shakes bad in park when on incline
Running fine at 70mph and went to nuturl mode racing the motor on interstate!! What’s worng??
In my 2003 four-wheel drive Dodge Durango 4.7 liter V8 545rfe transmission when it goes to shift from 2nd to 3rd it acts like it goes into neutral that is when I’m taking off in Drive if I take off in drive 2 it’s just smoothly out of first second 3rd will not shift out of 3rd just stays in 3rd and drive all day like that don’t recommend it I’m sure but that’s what it’s doing could that possibly be my shifting solenoids
car running fine pulled in driveway car would not move gear shifter would not engage