How to Replace the Downshift Solenoid in Your Car

On automatic transmissions, several sensors, including the speed sensors, mass airflow sensors and throttle position sensor, contribute and input digital information to the powertrain control module (PCM) and the transmission control module (TCM) so that your car can make proper adjustments based on driver commands. Each time a gear change is needed, the car’s computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the right gear.

When the brakes are applied, the need to downshift is managed using the downshift solenoid. Failing downshift solenoids will cause RPMs to remain high instead of dropping when the brakes are applied. This can also cause pressure issues elsewhere and serve as a potential threat to the other fragile components of an automatic transmission.

Solenoids rarely fail intermittently. They typically work well or they don’t work at all. If you feel there is a problem with the downshift solenoid, you can replace it on your own.

Part 1 of 3: Prepare to remove the downshift solenoid

Materials Needed

Step 1: Disconnect the negative battery cable. When working on any electrical system in your vehicle, always disconnect the negative battery cable. Disconnect the black cable that is connected to your battery by a bolt. Unscrew the bolt, remove the cable from the battery terminal and set it aside, keeping it away from anything metallic.

  • Note: Any time you are working with the battery is a good time to check for damage. Look for damage to the battery, terminals, or bolts.

  • Tip: Any corrosion on the battery terminals can be easily cleaned off at this time. Use a wire brush to remove any corrosion. You can also use chemicals or more natural products to help dissolve the corrosion.

How to Replace Your Vehicles Downshift Solenoid 2

Step 2: Raise and secure the vehicle. Raise the vehicle using a jack on the end of the vehicle where the transmission is located. Secure the vehicle with jack stands.

  • Note: It is good practice to put old tires, railroad ties, wood blocks, or other objects under load bearing parts of the vehicle. If the jack stands ever fail, or if the vehicle shifts off of the stands, doing this will give you a level of protection from the vehicle landing directly on top of you.

How to Replace Your Vehicles Downshift Solenoid 3

Step 3: Drain the transmission fluid. Remove the transmission fluid drain plug from the transmission pan. Allow almost all of the fluid to drain out.

How to Replace Your Vehicles Downshift Solenoid 4

Step 4: Remove the transmission fluid pan. One by one, gradually loosen all the retaining bolts around the perimeter of the pan. This decreases any chances of damaging the bolts or their counterparts.

Remove the transmission fluid pan from the transmission.

Part 2 of 3: Remove the downshift solenoid

Step 1: Locate the downshift solenoid. The actual location of the downshift solenoid for your vehicle will vary by make and model. Refer to the owner’s manual for your vehicle or search online to find exact diagrams of the location of this solenoid for your specific vehicle.

How to Replace Your Vehicles Downshift Solenoid 5

Step 2: Disconnect wiring from solenoid. Disconnect the wiring terminal plugged into the damaged solenoid and set it aside. This should be a simple fastening device holding the wires into the solenoid designed for a quick disconnection.

Step 3: Remove the solenoid. At this point, the solenoid should be free from all restraints and should pull or twist out.

Part 3 of 3: Replace the solenoid

Step 1: Replace the solenoid. With the old solenoid removed from the vehicle, do a visual inspection to ensure that the replacement is going to fit properly. Wipe the surface of the solenoid’s seat if it is wet and insert the new solenoid in the same way that you removed the last one.

Step 2: Attach the wiring harness. Reattach the wiring terminal that you had set aside earlier and plug it into the downshift solenoid.

Step 3: Reattach the transmission pan cover. Align the holes on the transmission pan with the holes on the transmission. Start by bolting the corners of the pan, to secure it while installing. Again, one by one, start to screw in all the retaining bolts and gradually tighten them together. This ensure that nothing is damaged or strained.

Step 4: Refill the transmission fluid. Locate your vehicle's transmission fluid fill spout (often the dipstick spout) and refill using the amount of transmission fluid specified for your vehicle.

How to Replace Your Vehicles Downshift Solenoid 6

  • Note: Some vehicles use a very specific transmission fluid according to the manufacturer’s preference. Refer to the owner’s manual to determine the type of transmission fluid recommended by the manufacturer.

Step 5: Test the transmission function. With the vehicle reassembled, and transmission fluid topped off, start the vehicle and allow it to idle in park for one minute. This gives the vehicle time to circulate the transmission fluid.

Test drive the vehicle in an open area with low traffic. Look for proper downshifting while braking and proper upshifting while increasing in speed.

Downshift solenoids are a critical part of automatic transmissions. Without a functioning set of solenoids, your vehicle's transmission will perform poorly and you also risk damaging other components in your transmission.

Transmissions can be tricky, especially automatic transmissions. If you are not comfortable with performing this process on your own, you can always get a certified technician from YourMechanic to replace the downshift solenoid and perform a transmission fluid service for you.


Next Step

Schedule Oil Change

The most popular service booked by readers of this article is Oil Change. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Oil Change reviews

Excellent Rating

(21,699)

Rating Summary
20,382
845
179
87
206
20,382
845
179
87
206

Matthew

33 years of experience
991 reviews
Matthew
33 years of experience
Volkswagen Passat - Oil Change - Hampton, Virginia
Matt always does a great job. Very professional. I look forward to my next appointment.... A++++++
Ford Expedition - Oil Change - Hampton, Virginia
I am so please to have Matt work on my vehicle, he is very friendly and personable, and always does a great job.

Greg

22 years of experience
37 reviews
Greg
22 years of experience
Audi A3 - Oil Change - Queen Creek, Arizona
Job well done! Greg was on time and professional. He treated my vehicle with care. He completed the job smoothly and so far so good. First time using Your mechanic and it was a pleasant experience. I will be looking into them again. Thanks Greg!
Ford Explorer - Oil Change - Scottsdale, Arizona
Greg was very friendly and professional. Communication was great, he let me know what he was doing. He went above and beyond to make sure everything was running smoothly. I would 100% recommend Greg!

LAVELL

27 years of experience
93 reviews
LAVELL
27 years of experience
Buick Encore - Oil Change - Oakland, California
Another home run! Really appreciate the flexibility regarding my service appointment. Due to my work schedule I desperately needed a late appointment. So grateful my car is receiving top shelf professional service. Replaced a oil pan drain plug that was seriously damaged and stripped by a competitor that will NEVER get my business again! All services were quickly completed. Thank you so much for another great experience with my.... Your Mechanic Lavell 5 ⭐️ Service consistently.

Brian

23 years of experience
483 reviews
Brian
23 years of experience
Porsche 911 - Oil Change - Ponte Vedra Beach, Florida
Brian is extremely knowledgeable and very personable and has taken very good care on my 911. I would recommend Brian to any one who has mechanical car challenges. I would recommend Brian to all My friends and family

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How to Replace a Lost or Stolen Car Title in Oregon
It's It's hard to keep track of all our important pieces of information and ID. Your car title is one of those items you may have lost track of over the years, and suddenly now that you're ready to transfer...
How to Replace Your Car Idle Air Control Valve
The IAC valve, or idle air control valve, dictates your vehicle’s idle. A faulty valve can lead to rough idling and stalling, among other problems.
How Long Does a Variable Valve Timing (VVT) Solenoid Last?
One One of the biggest concerns that most people have about their car is how it runs and idles. Most car owners fail to realize just how many different components have to work together in order for this type of...

Related questions

Truck clicks one time but wont turn over.

Hi there. If the starter was replaced, first check the battery cables to the starter and make sure that they are tight. If the cables are tight, then the issue could be that the clutch may have broke causing the...

How long does it take to replace the control arm assembly in a Mercedes-Benz S 500?

Hi there. The time for removing and replacing a control arm on a 2000 Mercedes-Benz S500 ranges between 4 to 6 hours depending on the persons experience and if the parts come off easy or not. If you need further...

Car stalling and there is a strong gasoline smell.

Hi there. There could be an electrical issue with the cluster panel on the dash causing the gauge to malfunction. For the fuel smell, there could be a vapor fuel line that is cracked under the vehicle or the purge...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com