Hyundai Transmission Problems

Hyundai vehicles are known for their reliability and fuel efficiency, but like any other car, they can experience problems with their transmission system. Transmission issues can be frustrating and costly to repair, but you can diagnose and troubleshoot the problem quickly with the right information. In this article, we will explore the common causes of transmission problems in Hyundai vehicles, as well as the symptoms and troubleshooting steps that can be taken to fix the problem.

One of the most common issues with Hyundai transmissions, affecting even new vehicles, is hard shifting or jerking when the engine is still cold. Once the engine and transmission fluid warm up, shifting is normal after about twenty minutes of driving. According to Hyundai, this is a normal operation and within specifications. We will also discuss the importance of timely maintenance and the use of the right transmission fluid to ensure the longevity and reliability of the transmission system. Whether you’re a Hyundai owner or a car enthusiast, this guide is designed to provide valuable information and help you make informed decisions about the performance and safety of your vehicle.

Symptoms

• Transmission won’t shift or engage.
• Check engine light comes on.
• Hyundai won’t move when placed in Gear / Drive.
• Erratic shifting when cold
• The transmission gets stuck in gear / limp mode.
• The transmission is stuck in the park.
• Vehicle speed is limited to 30mph.
• Transmission between 1st-2nd-3rd gears when cold

Causes

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 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. Changing the transmission fluid and filter will most likely not fix the problem, and a transmission rebuild or replacement may be necessary.
• Transmission range switch – The switch is mounted atop the transmission housing. It is connected to the shifter in the center console, which changes the transmission gears between Park, Neutral, Reverse, and Drive. This is a common problem in many models, including the 2001 to 2006 Hyundai Elantra and the 2005 to 2009 Hyundai Tucson. It can affect other older models and Hyundai Veloster, Sonata, Genesi, and Santa Fe. The selector may rust and not go in gear or back to Park.
• Torque converter or oil pump failure – The 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 cause erratic shifting. Especially when cold or when downshifting. Software glitches 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 – This can prevent the 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.

Hyundai 6-speed transmission problems

Hyundai’s 6-speed transmission is a common transmission found in many of their vehicles, and like any other mechanical component, it can have issues. Some common problems reported by Hyundai owners with the 6-speed transmission include:

• Delayed shifting: This can be caused by a malfunctioning transmission control module, a problem with the transmission’s internal components or a lack of proper maintenance.
• Rough shifting: This can be caused by worn synchronizers, bushings, gears, or bearings.
• Leaking or low fluid levels: This can cause damage to the transmission and cause problems with shifting.
• Overheating: This can be caused by clogged coolers, lack of fluid or worn internal components.
• Warning lights on the dashboard include Check Engine Light, Transmission warning light, or Gear ratio error indication.

It is important to have any symptoms of transmission problems checked out by a qualified Hyundai technician as soon as possible to prevent further damage. Regular maintenance, using the correct transmission fluid, and being aware of any recalls that may affect your vehicle are important to ensure the longevity and reliability of the transmission system.

Hyundai 8-speed transmission problems

Hyundai’s 8-speed transmission, also known as the 8-speed Automatic Transmission (8AT), is a relatively new addition to their lineup of vehicles, and as with any new technology, it may have some issues. Some common problems reported by Hyundai owners with the 8-speed transmission include:

1. Shuddering or jerking: Some drivers have reported experiencing a shuddering or jerking sensation when the transmission shifts gears. Various issues, including low transmission fluid levels or worn transmission components, can cause this.
2. Delayed shifting: Another common issue is a delay in the transmission shifting gears. This can be caused by a malfunctioning transmission control module or sensor or a problem with the transmission’s internal components.
3. Rough shifting: Some drivers have reported experiencing rough shifting when the transmission changes gears. This can be caused by worn or damaged internal transmission components or a problem with the transmission control module or sensors.
4. Overheating: Overheating of the transmission can lead to various problems, including rough shifting, delayed shifting, and transmission failure. Low transmission fluid levels, clogged transmission oil coolers, or other issues can cause it.
5. Warning lights on the dashboard: Warning lights on the dashboard can be caused by various issues, including low transmission fluid levels, malfunctioning sensors, or other transmission-related problems.

It is important to note that not all 8-speed transmissions have the same issues and that various factors could cause the problems. If you experience any of these problems, it is best to take your vehicle to a qualified Hyundai technician who can diagnose and repair it.

Hyundai CVT Transmission Problems

The CVT is found in a handful of Hyundai models, including the Accent and Elantra, plus the 2022 Kona and Santa Cruz.

Symptoms of failure of Hyundai CVT transmission include:

• Warning lights on the dashboard, including the Check Engine Light.
• Transmission warning light.
• Loud whining or humming noise while driving.
• Reduced fuel efficiency or increased fuel consumption
• Difficulty in maintaining a steady speed or acceleration

It is important to note that other mechanical issues can also cause some of these symptoms, so it is important to have the vehicle diagnosed by a qualified Hyundai technician to determine the root cause.

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 for your Hyundai apply to the transmission. Let’s 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 return to Park. Try this temporary solution:

1. Set the emergency brakes.
2. Move the shifter to Neutral.
3. Keep the brake pedal pressed, then turn off the ignition.
4. Turn the ignition back on.
5. Move the shifter to Park.
6. Turn off the engine and remove the key.

This problem can be caused by a faulty brake switch, ignition interlock module, or 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 the 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 with a transmission oil dipstick is easy.

Procedure:

1. Park the vehicle on level ground.
2. Set the parking brakes.
3. Start up the engine and move the shifter between the gears while parked.
4. Turn off the engine and open the hood.
5. Locate the transmission dipstick (not the engine oil dipstick).
6. Remove it and wipe it clean with a lint-free cloth.
7. Reinsert the dipstick, remove it, and read the transmission fluid level.
8. If the level is in the recommended cold range, drive the vehicle for twenty minutes.
9. Repeat the procedure to check the transmission fluid level when the transmission fluid is warm.

Only add the recommended Hyundai automatic transmission fluid if the level is low. See your owner’s 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.

The gear range selector is mounted on top of the transmission. This switch is connected with a cable to the shifter inside the car, allowing you to select the gear, Drive, Reverse, and Park. The gear selector can rust, or the cable connecting it to the shifter can also rust.

When this happens, moving the shifter or placing the car in Park is hard. Inspect the gear selector range. Spraying penetrating oil may allow you to shift back into the park. Be cautious not to spray it on the electrical connector next to it. Also, the cable may need to be adjusted.

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.

The YOUCANIC Full System Scanner can read and clear fault codes through every vehicle’s control module.

1. Locate the diagnostic port under the dashboard.
2. Plug your scanner and power it up.
3. Turn on the ignition, but do not start the engine.
4. Select Hyundai from the main menu.
5. Select Control Units > Transmission.
6. 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.

A generic code reader can be helpful but is not recommended as it only shows generic fault codes such as P0700, P0705, and 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 and output sensors, gear shifter position, and more.

Should I use a transition fix additive?

Many readers ask if they should use a transmission additive to fix shifting issues. Before trying any additives, we strongly recommend diagnosing your Hyundai transmission by a professional auto mechanic or Hyundai dealer. If your transition has failed and requires rebuilding or restoration, try a transmission fix like Bars Leaks Transmission Fix or Lucas Transmission Fix.

Transmission additives can help reduce friction, wear, and heat within the transmission, which can help improve the overall performance and extend the transmission’s life. However, it is important to note that transmission additives should not be used as a substitute for regular maintenance and repairs. Transmission additives can help in certain issues like preventing or reducing shuddering or slipping, but it will not fix severe transmission problems such as worn or damaged internal components, low fluid levels, or problems with the transmission control module.

There is no guarantee that these will fix your transmission. Transmission additives can not fix internal mechanical problems. If you see any improvement, do not expect transmission fix additives to be a long-term solution.

Troubleshooting 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 the 2nd, 3rd, and 4th gear.

Other problems included shifting to reverse, which 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.

Possible causes

• This problem is usually caused by leaking solenoids within the valve body. This is a gradual process, which starts only when cold and gets worse with time. The only solution is replacing the whole solenoid set with new or upgraded ones.
• 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 four-speed automatic transmissions 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. The onboard diagnostic system memory might have a check engine light and fault codes.

Possible causes

• 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, 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, found on models such as the 2006–2014 Hyundai Veracruz, can have issues with shift flares during acceleration and delayed downshifts braking, and stopping. Initially, the problem is only present when it is cold and accelerates slowly but it gets worse with time. In most cases, there will be no other symptoms.

Possible causes

• 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 persists 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.

Burning smell

In some situations, Hyundai cars with four-speed and six-speed automatic transmissions can produce a strong burning-oil smell. In most cases, this will be accompanied by an ‘Overheating transmission’ warning. A burning smell 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.

Possible causes

• 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, sludge might be inside the transmission oil cooler. Perform a transmission fluid flush; replace the cooler if it doesn’t help.

No acceleration or very sluggish acceleration

Hyundai cars equipped with a seven-speed dual-clutch (7DCT) transmission can suffer from sudden and intermittent loss of drive. Although the transmission will be in Drive and the 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.  There will be no check engine light or other apparent symptoms.

Possible causes

• This well-known problem 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.’ Reprogramming 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 when accelerating.  Symptoms 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.

Possible causes

• These transmissions use a dual-mass flywheel, which can wear out and develop excessive play. This causes a metallic rattle while idling. Check the flywheel condition and replace it if there is any movement between the plates.
• A worn dual-clutch assembly as a result of normal wear-and-tear. Although repair kits allow partial repair, replacing the clutch assembly is usually the best solution.
• Delays in response can result from overheating clutch assembly, which sticks to the flywheel surface. This can happen due to either too aggressive a 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 standstill.

Recall

Hyundai announced a recall of 53,142 cars and SUVs from the 2021 and 2022 models equipped with an eight-speed dual-clutch automatic transmission. The recall was issued due to concerns that the transmission oil pump malfunction could trigger an improper fail-safe mode reaction, causing the transmission to disengage. This recall highlights the importance of regular maintenance and the use of the right transmission fluid to ensure the longevity and reliability of the transmission system, as well as being aware of any recalls that may affect your vehicle.

Letters notifying vehicle owners of the recall were sent out on December 5, 2022. If you have questions or concerns, contact Hyundai customer service at 1-855-371-9460.

Conclusion

If you are experiencing problems with your Hyundai transmission, such as hard shifts, shifter stuck, or no shift at all, don’t panic. This guide covers problems that affect Hyundai transmissions, common symptoms, possible fixes, and how to read transmission codes yourself. Hyundai cars, vans, and SUVs can suffer transmission problems, especially if not maintained.

If you have Hyundai transmission problems, check the transmission fluid level first. Check to ensure no open recalls for your vehicle related to the transmission. Next, read the fault codes with a Hyundai OBD-II scanner and inspect the gear selector range switch.

Have a certified ASE mechanic or Hyundai dealer troubleshoot your vehicle if you cannot fix your Hyundai transmission yourself. The typical diagnostic fee ranges from $130 to $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 well by Honda and Toyota.

Frequently Asked Questions

We hope you find the Hyundai Transmission Problems guide helpful. Check these troubleshooting and repair guides for more help on your Hyundai.