Are you experiencing weird shifting issues and erratic error messages on the dashboard? The shift solenoid is one component that can cause a lot of weird issues with your automatic transmission if it is bad.
Changing a shift solenoid can be quite costly, and you do not want to spend money replacing a functioning solenoid. So, what are the typical symptoms of a bad shift solenoid?
The most common symptoms of a bad or faulty shift solenoid include hard shifting, stuck in gear, rough shifting or any variety of shifting problem you are noticing in your automatic transmission. You may also get a transmission warning light or other warning lights manifesting on your dashboard.
This is simply a brief overview of the symptoms that can present when you have issues with a faulty shift solenoid. In this guide you can more thoroughly read about the common symptoms, location, replacement cost, and how to diagnose the shift solenoid.
What Is A Shift Solenoid?
The shift solenoid is an integral element of an automatic transmission, or semi-automatic transmission, that acts as an electromagnet that controls the flow of fluid to actually change gears, and other functions in the transmission.
The transmission control unit is reading inputs from the engine, vehicle speed sensors, and many other sensors. Then the transmission control module uses all of this information to determine when it’s the right time to shift to the next gear.
When the transmission control unit has determined it’s the right time to shift, it then sends power or ground to the appropriate shift solenoid and it causes the solenoid to open which then allows the transmission oil to flow in to the valve body which then shifts to the next gear.
Shift Solenoid location
The transmission shift solenoids are located internally within the valve body of your automatic transmission.
For the majority of vehicles, you will not be able to visually see the solenoids without removing the valve body because they are incorporated within the valve body. Some car models will allow you to see them without removing it, but on the majority of cars the valve body must be removed to access them.
In the above picture you can see the shift solenoids attached to the valve body. They are the colored tubes with yellow, green, and black.
Signs of a Bad Shift Solenoid
Let’s discuss the signs of a bad shift solenoid.
#1. Check Engine Light.
The first sign of a bad shift solenoid is probably going to be the check engine light. The check engine light will come on even if there are issues with the transmission.
Typically, if you connect an ODB2 scanner to read the trouble codes, you should probably see a P0700 Trouble code. This code basically means there is a problem with transmission control. Additional trouble codes should be in the transmission control module.
#2. Transmission Warning Light.
Some vehicles may have a specific warning light for the transmission. If you have this light as well, there is most likely a trouble code relating to the bad shift solenoid stored in the memory of the transmission control module.
Assuming you are using a suitable OBD2 scanner to read the trouble codes in the transmission control module, you will be able to read the generic and enhanced trouble codes. Keep in mind that some OBD2 scanners only read codes from the engine control module, and are usually the lower cost OBD2 scanners.
#3. Shifting Delays.
If the transmission control unit determines there are shift solenoid issues, it could result in delayed transmission shift. This could be delayed for either upshifts or downshifts, or both.
#4. Skipping Gears.
You may also notice the car having an issue engaging into some gears. If it skips or jumps from one gear to another without engaging, that is another major indicator that you are having transmission shift solenoid issues.
You have one or more shift solenoid for each gear, if one is defective, it will have no choice but to skip to the next gear and not shift into that gear.
#5. Stuck In Gear.
If a shift solenoid got damaged while the gear was engaged, it would keep the transmission stuck in that gear. If this happens, you can try to apply external power to the shift solenoid to try and release the gear, if you know how to do it.
#6. Downshift and Upshift Issues.
It is also possible to have intermittent issues with the shift solenoid. As an example, downshift or upshift problems could result in severe hard shifts, or shifting at way too low or to high of RPM’s.
#7. Limp Mode.
Limp mode is a protective mode for your engine. You will mostly notice limp mode if your engine gets RPM limited to 2500-3000 RPM, and that your transmission shifts might be affected.
Limp mode activates specifically to keep the transmission shifting at gear 3, and it is possible that if you’re vehicle has a bad shift solenoid it could turn on limp mode.
Cost of Shift Solenoid Replacement
The cost to replace a shift solenoid is between $100 – $350, and for a shift solenoid pack it is between $400 – $700. This cost includes transmission fluid, filter, parts, and labor.
The replacement cost of a shift solenoid can vary much depending on the car model and transmission model.
As I said before, with some cars you cannot just replace one solenoid. You need to replace the whole solenoid pack, or in some cars the whole valve body, which can be quite expensive.
When you replace a shift solenoid, valve body, or solenoid pack, you should always replace the transmission fluid and filter.
The prices listed are inclusive of parts and labor but do not include diagnosis and fluid replacement.
- Single shift solenoid replacement cost: $50-150$
- Shift solenoid pack replacement cost: $300-600$
- Valve body replacement cost: $500 to $1000
Price also vary largely based upon the quality of parts and transmission fluid that you are choosing to use. Aftermarket parts are generally cheaper than original parts but usually not of the same quality.
Many car models such as Hyundai have technical service bulletins specific to the shift solenoids and it is recommended that you check for any technical service bulletins for your Vehicle.
How to Diagnose a Shift Solenoid Problem?
Initially, we need to determine if the issue is caused by wiring, shift solenoid, TCM issue, or mechanical problem. You need to read and research the trouble codes to fully understand the problem before beginning troubleshooting.
If the trouble codes indicate that it is stuck or an electrical issue, you most likely have a wiring or shift solenoid issue, so you would need to inspect and perform tests on the shift solenoids.
For many shift solenoid related codes, the resolution may just be a transmission fluid swap or doing a transmission flush. Generally, a transmission fluid swap is not particularly costly, so it’s well worth it.
When it comes to diagnosing issues regarding the shift solenoid, utilizing a diagnostic scanner is crucial.
Below is a list of how to perform the diagnostics with a scanner:
- Find a transmission wiring diagram for your transmission.
- Find out which pins on the wiring harness go to the affected shift solenoid.
- Loosen the transmission wiring plug on the transmission
- Pull out the OBD2 scanner and start the output test for the affected shift solenoid.
- Within the output test, use the multimeter to see if you are able to get 12 volts and ground at the plug on the transmission at the correct pin related to the shift solenoid.
If you are not getting both 12 volts and ground, you may have a wiring issue or the TCM may be faulty.
If you are getting 12 volts and ground and the shifted solenoid trouble code keeps reappearing after you have cleared the code, you may have a faulty shift solenoid.
Common Shift Solenoid Trouble Codes
- P0750 – Shift Solenoid A
- P0752 – Shift Solenoid A – Stuck Solenoid @ ON
- P0753 – Transmission 3-4 Shift Solenoid – Relay Circuits
- P0754 – Shift Solenoid A – Intermittent fault
- P0755 – Shift Solenoid B
- P0756 – AW4 Shift Sol B (2-3) – Functional Failure
- P0757 – Shift Solenoid B – Stuck Solenoid @ ON
- P0758 – Shift Solenoid B – Electrical
- P0759 – Shift Solenoid B – Intermittent fault
- P0760 – Shift Solenoid C
- P0761 – Shift Solenoid C – Performance or Stuck Off
- P0762 – Shift Solenoid C – Stuck Solenoid @ ON
- P0763 – Shift Solenoid C – Electrical
- P0764 – Shift Solenoid C – Intermittent fault
- P0765 – Shift Solenoid D
- P0766 – Shift Solenoid D – Performance or Stuck Off
- P0767 – Shift Solenoid D – Stuck Solenoid @ ON
- P0768 – Shift Solenoid D – Electrical
- P0769 – Shift Solenoid D – Interm
- P0770 – Shift Solenoid E
- P0771 – Shift Solenoid E – Performance or Stuck Off
- P0772 – Shift Solenoid E – Stuck Solenoid @ ON
- P0773 – Shift Solenoid E – Electrical
- P0774 – Shift Solenoid E – Intermittent fault
Can you drive with a faulty shift solenoid?
While driving with a faulty shift solenoid may be possible, it is not worth it.
Driving with a faulty shift solenoid can do further damage to the transmission and will cost you more money overall than the cost of repairing the shift solenoid now.
Can you replace the shift solenoid yourself?
Whether you can replace the shift solenoid yourself will depend on what make and model car you are driving and how much experience you have. Some shift solenoids can be changed with limited difficulty by removing the transmission and valve body with a repair manual.
However, it will be hard to change the shift solenoid on most makes and models and requires a computer after the solenoid has been replaced.
How do you fix a stuck solenoid?
In some cases, you will be able to fix a stuck shift solenoid by changing the transmission oil and filter and doing a transmission fluid change. In most cases the stuck solenoid will not release and will require the replacement the shift solenoid if a fluid change does not alleviate the problem.
How many shift solenoids are in a transmission?
Most transmissions contain usually 2 to 5 shift solenoids but the number can vary based on the make and model of your car. The primary role of shift solenoids is simply to control the flow of hydraulic fluid to the clutch packs within the transmission that allows for shifting between gears.
If you are experiencing the above bad shift solenoid symptoms and are unsure about diagnosing the problem yourself, then it is time take your car to a mechanic. The mechanic will be able to diagnose what the problem is, and hopefully fix the problem without replacing the whole transmission.
Worn shift solenoids are a common problem in older automobiles, so if you have an older vehicle this is an item to be aware of.