Signs Of Transmission Solenoid Problems & Its Solutions (Solved)

The transmission solenoid is a component that keeps your car going because it controls the flow of transmission fluid. Due to lack of upkeep and care, the solenoid can get worse and show symptoms due to underlying certain problems.  

Since you are here to find out about the signs of transmission solenoid problems, chances are your system is already misbehaving.

Well, here’s a brief overview of the common signs:

  • CEL (Check Engine Light) turns on.
  • Gear shift delays or act weirdly.
  • Stuck gear to N (Neutral) or don’t shift.
  • The car switches into limp mode.
  • Annoying Engine Noises

To know what these signs mean and how to fix them, continue to read. I’ll explain all of these below…

5 Signs Of Transmission Solenoid Problems & Its Solutions!

I’m about to share all the solutions based on the signs and explain the reason too. It’ll take on average 20 minutes to fix each issue at a time (not more than 1 hour). Let’s dive into the procedure!

Sign #1: CEL (Check Engine Light) Turns On.

This is the initial sign a faulty transmission solenoid will show. It pops up on the dashboard when the TCM (Transmission Control Module) senses a system error with sensors. This cause the CEL to turn on and blink to grab your attention. 


  • First off, stop driving immediately after you notice the light coming on.
  • Take an OBD II scanner like the ANCEL AD310 Classic that is universal to clear fault codes and connect the plug to the truck. 
  • Turn the scanner on through the power button and access it. 
  • If it automatically scans, wait for 5 – 10 seconds to locate any error code on TCM. Here are some mentions of trouble codes:
    • P0750 – Shift Solenoid A.
    • P0755 – Shift Solenoid B.
    • P0760 – Shift Solenoid C.
    • P0765 – Shift Solenoid D.
    • P0770 – Shift Solenoid E.

Even if there are multiple trouble codes and you’re confused, the scanner will allow you to retrieve relevant trouble codes.

  • Match the code and clear the code by pressing ‘Enter’ on the ‘Erase Codes’ option on the scanner. 
  • Wait for some while.
  • Turn on your car and look at the dashboard to ensure CEL doesn’t pop and blink for success.

Sign #2: Gear Shift Delay.

The next sign is a delay to shift gear which also is acting unusually. It’s because the solenoid might have got dusty and trapped with dirt over time. Another reason is dirty transmission fluid.

Due to these 2 reasons, the solenoid will restrict the pressure of fluid flow to shift from the opening and closing path. That causes the shifting gear to act lately when shifting.


  • Jack up the truck underneath.
  • If you notice the transmission fluid is dark brown, red, or black in colour or it has an odour, detach the drain plug to drain the transmission fluid. 
  • Use a wrench to remove the bolts from the transmission fluid pan.
  • Locate the transmission solenoid valves and remove them. Before doing it, wear safety gloves.
  • Apply moisturizing MAF sensor cleaner like Johnsen’s 4721 on the solenoid valves and outside the transmission fluid pan.
  • Attach all the transmission solenoid valves in their place. 
  • Place the fluid pan cover and insert the bolts to tighten them using a wrench.
  • Use transmission fluid to refill the transmission.

It’s also crucial to check the transmission filters and fluid levels of your vehicle regularly to prevent the problem.

Sign #3: Stuck Gear To N (Neutral) Or Don’t Shift.

Another common sign of a bad sensor or transmission solenoid is a stuck gear. Since it’s the sensor that transfers the signal to let your transmission decide when to shift, there’s a high chance that the stuck gear is a result of a bad sensor or solenoid.


  • Start the process by setting the emergency brake.
  • Now, take your key and insert it into the ignition. It will turn the ignition switch on.
  • Now, you have to remove a small plastic cap that locates on the shifter console near the shifter lever.
  • Take a nail file or a small screwdriver and insert it into the override slot. Just push it down and hold for a while.
  • At the same time when you keep holding down the shift, press the brake pedal.
  • Finally, hold the shifter and find the release button that locates on the shifter. Once you’ve found it, press that button. Now, just move the shifter to the neutral position and start your engine.

Yes, simply it should do the trick.

Sign #4: Car Switch Into Limp Mode.

Sometimes for safety purposes, the car can turn to limp mode especially when transmission solenoid problems occur. Due to this mode, your truck will automatically limit RPMs, speed, engine power, and sometimes stuck gear issues.

Don’t overlook the limp mode because this sign seriously indicates a danger to the engine of your vehicle.   


  • Use the OBD II scanner and connect it to the truck.
  • Turn on the truck display and scanner.
  • The scanner will run to automatically scan for error codes. Wait for 5 seconds.
  • After locating the error codes, erase the fault codes and press ‘Enter’.
  • Wait for around 1 to 2 minutes to complete the task.

If the steps do not work, make sure there’s an adequate level of clean transmission fluid in your vehicle. If it’s ensured, clear and check the engine light. Once it’s checked and it doesn’t work, turn off the engine and let your car fix all the limp mode issues.

Sign #5: Annoying Engine Noises

If you notice your engine starts making noise including humming, whining, or grinding, chances are there’s a bad transmission solenoid you need to take care of.

The starter of your car is a small electrical device and it consists of a solenoid and a motor. The solenoid supplies the battery energy of your car to the electric motor right after you crank the ignition. After that, the motor pushes the starter gear and the car starts.

But if the solenoid goes bad, you’re stuck.


Since it’s an internal issue, we suggest you consult an experienced mechanic when you experience this.

You may need to replace the solenoid or the whole starter. So, get your car checked by a professional, a DIY project can cause further damage here.

Still, if you’re sure that it’s the solenoid that causes the issue, here’s how to replace a bad transmission solenoid.

  • Find an empty place with a level surface and park your car here. Don’t forget to set the parking brake.
  • Now, find the negative battery cable and detach it. Also, take the transmission pan off.
  • No matter what amount of transmission fluid is there, drain the fluid.
  • Find where the transmission solenoid wiring harness is and gently disconnect it.
  • This time, gently remove the solenoid from your transmission.
  • Now, you can install the new solenoid. After the installation is done, don’t forget to reconnect the wiring harness.
  • Re-install the things you removed. I mean, set the transmission pan where it was and re-fill the transmission with clean and fresh fluid.
  • Finally, take the negative cable battery and reconnect it. You can start the engine immediately and whether there’s a leak.

If there’s no leak, you’re good to go.

Tips to Prevent Transmission Solenoid Failure

You’ve already known several reasons and solutions for a faulty transmission solenoid. Here are some common yet useful tips you should follow to get a long journey with your solenoid.

  • Keep the transmission fuel at the correct level and make sure the fluid is clean because dirty fluid can cause the solenoid to fail over time.
  • Get your transmission checked regularly. It’s because you should be sure that the solenoids are working properly. And, take action whenever you notice any problem.
  • Most cars are equipped with a transmission cooler. If you also have it, keep it clean and replace it when needed. Because a damaged or dirty transmission cooler results in overheating the transmission fluid which eventually leads to transmission solenoid failure.
Signs Of Transmission Solenoid Problems Infographic

Frequently Asked Questions

1. How many solenoids are in a transmission?

You’ll find 2 – 3 or more solenoids in the transmission based on your truck’s requirements. These are shift solenoid, lockup solenoid, and control solenoid.  

2. How much does transmission solenoid repair cost?

Usually, it might cost you around $250 – $550 to repair the transmission solenoid (single one). However, you might need to count the tax, labour cost, and other additional fees. It will charge no more than $3,500 based on the issues.

3. Where is the transmission solenoid located?

In most cars, the transmission solenoid is placed inside the valve body (of automatic transmission). To reach this part, you might need to remove the oil pan of the transmission and then take out the valve body.

Wrapping Up

Finding and checking all the signs of transmission solenoid problems will help you figure out the right solution to fix things well.

As it is a complex device, it will need strong care once a year and replacement after 2 to 3 years. Trying the above technique will save huge expenses from repair or replacement.

But yeah, you should get help from an expert if the above stuff seems tough to try.

Hope you find this content detailed and like it to get ideas in order to fix issues after matching the signs. Happy Fixing!

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William Baldwin

This Is William Baldwin, The Founder & Managing Editor of this website. Me and my team share automotive tips, tricks, and news

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.