Avoid expensive transmission solenoid problems by learning what solenoids are and how to operate them. More importantly, you need to know about the possible issues and when to seek help.
Your car carries a complex set of machinery that enables it to shift between the gears. In your transmission system, components such as sensors, fluid, hydraulics, and gears help your car accelerate and decelerate.
These components allow you to enjoy a smooth ride. Solenoids are the small valves that regulate the transmission’s operation and enable fluid to move when triggered by the engine or other sensors.
If your transmission starts causing problems, it might be due to solenoid. Other signs tell you to have a bad transmission shift solenoid as well.
But first, we will explore:
What Does a Transmission Solenoid Do?
Solenoids are small valves that operate your car’s transmission. These electro-hydraulic valves control the fluid flow within the transmission system. Solenoids do it by opening or closing when they receive electric signals.
Moreover, the engine, sensors, or even the transmission control unit send the signals and notify the transmission to kick in like the engine’s speed rises or falls.
In an automatic transmission, these solenoids are essential, and they ensure that automatic gear shifting occurs quickly. They also have the following types:
- Transmission shift solenoid
- Lockup solenoid
- Transmission control solenoid
When the engine or transmission control unit signals the solenoids, the valves will open or close to keep the transmission fluid moving.
And if the process slows down or fails, the shifting of gears will slip or fail due to the pressurization of the transmission clutch and bands.
That’s why you need to know the potential signs of solenoid problems to find a suitable solution before it’s too late.
Transmission Solenoid Symptoms
A solenoid starts to wear down after metal salts, constant transmission fluid exposure, and intense temperatures fluctuations. And it stops performing as it should.
This situation further leads to a series of severe symptoms. Car owners, sometimes, don’t know how to identify signs of a bad solenoid.
Here are a few signs that help you know when it’s time to seek help.
Unable to Downshift
A faulty solenoid cannot shift back down. You might even find it odd while decelerating. But you won’t notice this bizarre behavior when accelerating.
In this case, the problem is the outcome of a stuck solenoid in an open orientation.
It could occur from physical damage to the solenoid body. Or, it could be a result of bad wiring that stops the solenoid from receiving electrical signals.
Moreover, there might be a foreign matter that’s restricting the solenoid from shifting. It happens due to contaminated transmission fluid.
Pressure is essential to run a transmission. In simpler words, your transmission moves from gear to gear due to the changes in its internal pressure. This pressure is achieved through the movement of the solenoids.
However, when a solenoid ages or begins to break down, it showcases a noticeable difference in carrying out the functions that enable your transmission to shift.
It may result in disconcerting “gaps” between one gear to another. In other cases, you might even feel that your car has lost power. Because your sluggish solenoids struggle to move into their new positions.
Unstable Gear Shifts
If you’re looking for an easy sign to know a bad transmission solenoid, know that its unpredictable gear shifts. For example, while driving your car at a fixed speed, you may find that your vehicle jumps to another gear.
No doubt, this scenario is a stressful and dangerous one. However, unpredictable shifting occurs due to the solenoids opening or closing without receiving any signal from the transmission computer.
It happens for two reasons; bad solenoid wiring or physical breakdown that hinders the solenoid from maintaining its proper position.
Remember, these untimely gearshifts take place in any direction. For example, your car might jump to the next lowest gear leading your RPM to spike suddenly. It may jump to a higher gear as well.
This situation might make your car stalling out. Whatever the case is, it’s essential to seek the assistance of a transmission expert at the earliest.
Check Engine Light Comes On
When your Check Engine light comes on, don’t take it lightly. It’s a sure sign that you need to schedule an appointment with a repair shop for diagnosis.
With the Check Engine on, your transmission might go into Fail Safe mode, indicating driving your car will be difficult.
More importantly, your power and available gears will be limited. Therefore, you will experience a noticeable change in driving.
The transmission control module detects failure ranging from severity from a broken solenoid to a blown fuse that will trigger the limp mode.
It alerts limp mode to prevent further engine or transmission damage. When the limp mode is activated, the car can still work, but it allows driving in a limited capacity.
Moreover, the limp mode affects the bad transmission solenoid. It allows your car to go into the second gear and remain there.
This situation leads to a slow feeling when you drive and prevent full acceleration. It also boosts RPMs to go with the same speed.
Remember, it’s not suggested to drive your car when it’s in limp mode for too long, as it will lead to further damages.
Diagnostic Trouble Codes
When the transmission control module notices an issue with one of the monitored systems, it activates a diagnostic trouble code.
The trouble codes for the primary transmission component that showcase bad solenoid signs start at P0700—the codes for the solenoid range from P0751 to P0758.
How Does the Transmission Solenoid Work?
If you’re curious how transmission solenoid works, know that they run by an electrical current that the transmission controller or computer supplies.
The process involves a series of steps. First, the transmission computer sends out the instructions to the individual transmission solenoid.
Then, it sends transmission fluid directly to specific clutch packs or servo valves to control gear shifting suitable to the given engine requirements or driving conditions.
Moreover, a transmission solenoid consists of nine parts that work together to operate it properly. Following are those parts:
- A spring
- An orifice
- A plunger or piston
- An inlet port
- An outlet port
- Lead wires
- The valve body
- The coil winding
- The solenoid coil body
Transmission Solenoid Replacement Cost
It’s good to be aware of solenoid replacement costs. Therefore, remember, in most cases, solenoids are placed inside of the oil pan, connected to the valve body.
Depending on the make or model you drive, the repair expert can replace only the faulty shift solenoid. However, in other cases, the solenoids are available in several unit packs.
If there’s a problem with one, you might need to replace the entire pack. It requires 2-4 hours to complete the job.
And the required shop time is estimated at $60-$100 per hour. Moreover, if you want to know the average diagnosis cost and replacement, it ranges between $150 to $400.
On the other hand, transmission solenoid cost for a single solenoid is different. You can expect to pay between $15 to $100. And a pack can cost between $50 to $300.
It’s common for transmission shift solenoids to wear out over time. But you can increase their lifespan by changing transmission fluid. This change needs to be done at the factory-recommended intervals.
What Does a Transmission Solenoid Look Like?
The solenoid body is made of steel and has a cylindrical shape. Transmission Solenoids have a valve and return spring in them.
Moreover, the solenoid coil consists of a wire wound around a conductive component that serves as an electronic magnet while controlling the valves position.
How does an Automatic Transmission Solenoid Shift Work?
In an automatic transmission, the shift solenoid shifts the car’s gears for you.
Your vehicle’s computer, such as the transmission control unit, takes information from the engine, speed sensors, and other parts to determine the right time to shift gears for power, fuel efficiency, and other operation.
When the control unit decides to shift the transmission, it sends power to activate the shift solenoid allowing transmission fluid to flow into the valve body.
This causes your car’s torque converter to change hydraulic pressure to shift gears.
But, remember, these are electro-mechanical parts. And they can experience failure and create hurdles when it comes to shifting between gears.
Frequently Asked Questions (FAQs)
- What happens when a transmission solenoid goes bad?
You can experience insufficient pressure, hard, soft, or delayed shifts when there’s a problem with one or more solenoids. A faulty shift solenoid can also lead to transmission slippage, causing your engine to revs faster, but the car’s speed remains the same.
- How much does it cost to replace a transmission solenoid?
The replacement will cost around $60 to $140 for one hour. It costs between $150 to $400 to get your vehicle inspected and replaced after diagnosing any problem. Single solenoids are available at $15 to $100 to buy. However, the entire pack will be expensive and can cost around $50 to $300.
- What are the signs of a bad transmission solenoid?
Transmission solenoid troubles will become evident in one of the four ways:
- Delayed gear shifting
- Transmission gets stuck in neutral
- Rough and choppy shifting gears
- Difficulty in downshift, the engine continues to rev even after applying the brakes.
- Can you drive with a bad transmission solenoid?
The answer is yes. Driving a car with a bad shift solenoid is possible. It might not shift after a particular gear, but you can drive it for a short time without the fear of severe damage.
- Is it hard to change a transmission solenoid?
If the fault requires you to replace the while solenoid pack, it will cost around $250 to $700. The repair facility may take between 2.5 and 5 hours to replace the solenoid pack and less time to replace a single solenoid.
- Where is a transmission control solenoid located?
The transmission solenoids are placed within the valve body, the transmission unit control, or the transmission control module. The control unit of a transmission is a device that monitors the automatic transmission. It can also use sensors to calculate the functionality of your car’s electrical part.
- What does a bad transmission solenoid sound like?
A bad automatic transmission will emit buzzing, whining, or humming sounds, whereas manual transmission emits harsher mechanical noises, such as clunking. Also, some of these noises may sound similar to an engine, driveshaft, exhaust system, wheel bearing, or differentials.
- Can you fix a transmission solenoid?
Once it’s finalized that you’ve got a faulty transmission shift solenoid, the only repair is to replace the failed part with the new one. You can hire any professional, visit an automobile dealership service, or can do it yourself too.
Transmission solenoids can go bad due to various reasons. Yes, you can drive with a bad solenoid for a short distance. But it’s better if you get it fixed.
When solenoids become faulty, they indicate certain signs; it’s imperative for you to keep an eye out for those symptoms.
Once you notice one of these signs, opt for the professional service and get it checked. These repairs can be stressful as they can impact your car’s ability to function.