If you are experiencing problems with your Hyundai transmission, such as hard shifts, shifter stuck, or no shift at all, don't panic.
In this guide, we go over problems that affect Hyundai transmissions, common symptoms, possible fixes, and how to read transmission codes yourself.
Hyundai cars, vans, and SUVs can suffer from transmissions problems, especially if not maintained.
One of the most common issues with Hyundai transmissions that can affect even new vehicles is hard shifting or jerking when the engine is still cold.
Once the engine and transmission fluid warm us, about 20 minutes of driving, shifting is normal.
According to Hyundai, this is normal operation and within specification.
Let's take a look at Hyundai transmission problems and common symptoms.
The most common problems with Hyundai transmissions:
- Low transmission fluid level - Common on Hyundai vehicles with over 100,000 miles. It can cause hard shifts, delayed shifting, or shifting at high RPMs.
- Input and output sensor - Failure of either one of these sensors will trigger the check engine light and erratic shifting. Hyundai transmission gets stuck in gear. Vehicle speed may be limited to 45 mph maximum.
- Clogged transmission filer - The transmission fluid filter may get clogged by metal shaving, clutch metal, or broken internal parts. At this stage, changing just the transmission fluid and filter most likely will not fix the problem, and a transmission rebuild or replacement may be necessary.
- Transmission range switch - The transmission range switch is mounted on top of the transmission housing. It is connected to the shifter in the center console, which is used to change the transmission gears between Park, Neutral, Reverse, Drive. This is a common problem in many models, including 2001 to 2006 Hyundai Elantra and 2005 to 2009 Hyundai Tucson. It can affect other older models and Hyundai Veloster, Sonata, Genesi, Santa Fe. The selector may rust and not go in gear or back to Park.
- Torque converter or oil pump failure - Vehicle won't move when the shifter is placed in Drive or Reverse. This is not a common problem but can be an issue on high mileage Hyundai vehicles with over 150,000 miles.
- PCM and TCM Problem - Issues with powertrain and transmission software can be the cause of erratic shifting. Especially when cold or when downshifting. Software glitch can cause harsh shifts at cold starts, especially in the newer 8-speed automatic transmission. This problem affects newer Hyundai vehicles, including Elantra, Sonata, Veloster, Santa Fe, etc.
- Brake light switch - It can prevent moving the shifter out or back to Park. It can also cause intermittent starting issues.
- Shifter - The shifter (gear selector) allows you to select the gear (PRND). When it fails, it can prevent the shifter from returning to Park, or you can not select the correct gear.
- Neutral safety switch - Can prevent vehicle start or cause the shifter to get stuck in Park. The engine will not start in Park, but it can start in Neutral.
A number of these Hyundai transmission problems are explained in-depth below.
Troubleshooting Hyundai Transmission Problems
If your Hyundai transmission won't shift, go in gear, or is stuck in 2nd or 3rd gear, there are a few basic things that you can check yourself.
First, check if any open recalls exist for your Hyundai that apply to the transmission.
Let's take a look at what you can do to troubleshoot a Hyundai transmission.
Stuck in Drive, won't go back to Park.
Hyundai transmissions are common problems because the gear shifter gets stuck and won't go back to Park.
Try this temporary solution:
- Set the emergency brakes.
- Move the shifter to Neutral.
- Keep the brake pedal pressed, then turn off the ignition.
- Turn the ignition back on.
- Move the shifter to Park.
- Turn off the engine and remove the key.
This problem can be caused by a faulty brake switch, ignition interlock module, or faulty gear range selector on the top of the transmission.
If the instructions above do not work, manually override the shifter to move it to the park.
Check Transmission Fluid Level
Low transmission fluid level is the most common problem that causes erratic shifting and no shifting on Hyundai vehicles.
Checking the transmission fluid on a Hyundai that has a transmission oil dipstick is very easy.
- Park vehicle on level ground.
- Set the parking brakes.
- Startup the engine, and while parked, move the shifter between all the gears.
- Turn off the engine and open the hood.
- Locate the transmission dipstick (not engine oil dipstick).
- Remove it and wipe it clean with a lint-free cloth.
- Reinsert the dipstick, remove it, and read the transmission fluid level.
- If the level is in the recommended cold range, drive the vehicle for 20 minutes.
- Repeat the procedure to check the transmission fluid level when the transmission fluid is warm.
If the level is low, only add the recommended Hyundai automatic transmission fluid.
See your owners manual.
Do not fill above the MAX mark on the dipstick.
If your Hyundai does not have a transmission dipstick, the level can be checked by removing the plug on the transmission side.
Inspect gear sector range switch
Read Diagnostic Trouble Codes
The next step is to read the diagnostic trouble codes (DTC) from the Transmission Control Module (TCM) with an OBD-II Transmission Scanner.
- Locate the diagnostic port under the dashboard.
- Plugin your scanner and power it up.
- Turn on the ignition but do not start the engine.
- Select Hyundai from the main menu.
- Select Control Units > Transmission.
- Scroll down, then select Read Fault codes.
The procedure is similar to reading the check engine light codes.
Use a Hyundai transmission scanner to get accurate fault codes and descriptions.
Using a generic code reader can be helpful but is not recommended as it will only show generic fault codes such as P0700, P0705, P0740.
Reading fault codes from the transmission module will better understand why your Hyundai transmission won't shift.
You will also be able to view live sensor data from the transmission control module, including data from the input, output sensors, gear shifter position, and more.
Should I use transition fix additive?
Many of our readers ask if they should use a transmission additive to fix shifting issues.
Before you try any additives, we strongly recommend having your Hyundai transmission diagnosed by a professional auto mechanic or Hyundai dealer.
There is no guarantee that these will fix your transmission. Transmission additives can not fix internal mechanical problems.
If you do see any improvement, do not expect transmission fix additives to be a long term solution.
Hyundai Transmission Problems by Symptoms
Slipping during gear changes or delayed reverse engagement
Older Hyundai cars with A4CF 4-speed automatic transmission suffer from a fairly common problem with gear changes.
There will be a noticeable slippage during gear changes between 2nd, 3th, and 4th gear.
Other problems included shifting to reverse can be delayed and followed by a clunk. These symptoms might be more noticeable when cold.
There might be a check engine light and corresponding codes in DTC memory.
- In most cases, this problem is caused by leaking solenoids within the valve body. This is a gradual process, which starts only when cold and gets worse with time. Replacing the whole solenoid set with new or upgraded ones is the only solution.
- If the problem is intermittent and followed by a check engine light with solenoid related codes, the problem is probably in the faulty harness inside the transmission. If the harness is damaged, there is a chance that solenoids are not the source of the problem.
Sudden shifting to Neutral or erratic shifting
Vehicles with 4-speed automatic transmission can suddenly shift to neutral while driving or idling in gear.
Although the gearshift is in Drive, it will refuse to engage any gear. In some cases, gear shifts will be very erratic.
There might be a check engine light and fault codes in the onboard diagnostic system memory.
- In most cases, this problem is in transmission input or output sensors, which can go bad. In some cases, this will trigger solenoid related codes. Replacing them in pairs, which is an easy job, is the only reliable way of repairing this issue.
Shift flares and delayed gearshifts
Hyundai cars with Aisin AW TF 80 6 speed automatic gearbox, which is found on models such as 2006–2014 Hyundai Veracruz, can have issues with shift flares during acceleration and delayed downshifts when braking and stopping.
Initially, the problem is only present when cold and accelerates slowly, but gets worse with time. In most cases, there will be no other symptoms.
- On any high-mileage car, check the service history first. As this transmission is considered ‘sealed for life,’ there is a chance that the transmission fluid was never changed. If needed, perform a detailed flush using only the approved transmission fluid.
- Using a suitable diagnostic tool, resetting transmission adaptation values, and installing the latest software version.
- If the problem is still present after performing the steps above, the cause is within worn valve body bores. This causes transmission fluid to leak around the solenoid pistons, resulting in shift issues. Replacing the whole valve body is the only solution, but many specialized workshops sell rebuilt ones because this is a well-known problem.
Hyundai cars with both 4-speed or 6-speed automatic transmission can produce a strong burning-oil smell in some situations.
In most cases, this will be accompanied by an ‘Overheating transmission’ warning. This usually happens only when towing a heavy trailer or during long, steep uphills.
There will be no other symptoms, and the vehicle will resume normal operation after cooling down.
- As this is a sign of transmission fluid overheating, check its level and condition. If needed, top-up or perform a transmission fluid flush.
- If the fluid changes have been neglected, there might be sludge inside the transmission oil cooler. Perform a transmission fluid flush, and if it doesn't help, replace the cooler.
No acceleration or very sluggish acceleration
Never Hyundai cars equipped with a 7-speed dual-clutch (7DCT) transmission can suffer from sudden and intermittent loss of drive. Although the transmission will be in Drive and engine revving, the vehicle will not accelerate.
In most cases, this happens after a shortstop with the engine running, such as waiting for a red light or similar.
There will be no check engine light or other apparent symptoms.
- This is a well-known problem that affects a series of cars and SUVs sold in the U.S such as Hyundai Sonata, Veloster, i30, Tucson, Ioniq, and Venue.
- This issue is a software glitch, which can cause the transmission to ‘freeze.’ Reprogram the transmission control unit with updated software solves the problem. A factory recall covered this issue, so check if your vehicle applies.
Shaking during accelerations or harsh shifting
Models equipped with dual-clutch transmissions can develop a series of issues that show up when accelerating.
This can range from delays in response, shaking and juddering while setting off from a standstill, or harsh shifting.
Most of these symptoms are more prominent when the driving style is more aggressive.
- These transmissions use a dual-mass flywheel, which can wear out and develop an excessive play within it. This causes a metallic rattle while idling. Check the flywheel condition and replace it if there is any movement between two plates.
- A worn dual-clutch assembly as a result of normal wear-and-tear. Although repair kits allow partial repair, replacing the whole clutch assembly is usually the best solution.
- Delays in response can be a result of overheating clutch assembly, which sticks to the flywheel surface. This can happen as a result of either too aggressive driving style or outdated software. Update the latest transmission control software using an appropriate diagnostic tool.
- Broken or worn engine or gearbox mounts. This allows excessive movement, causing the engine and gearbox to jump when pulling off from a stand-still.
- Transmission won't shift or engage
- Check engine light comes on
- Hyundai won't move when placed in Gear / Drive.
- Erratic shifting when cold
- Transmission gets stuck in gear / limp mode.
- Transmission stuck in the park.
- Vehicle speed is limited to 30mph.
- Transmission between 1st-2nd-3rd gears when cold
If you are having Hyundai transmission problems, first check the transmission fluid level.
Check to make sure there are no open recalls for your vehicle that are related to the transmission.
If you cannot fix your Hyundai transmission yourself, have a certified ASE mechanic or Hyundai dealer troubleshoot your vehicle.
Typical diagnostic fee ranges in the $130-$200.
Only use transmission fix additives as a last resort and remember that it will most likely be a temporary solution even if it fixes your Hyundai transmission.
Transmission problems are common among all car manufacturers.
In the early days, Hyundai had higher than normal failure rates.
Late-model Hyundai vehicles have improved significantly over the years. The current models are built as good as Honda and Toyota.
How do we know?
From tearing down several late models Hyundai, Honda, Toyota, Mazda vehicles.