P0731 on Hyundai: How to Diagnose & Fix
Gear 1 Incorrect Ratio
1 Hyundai model · 1 documented issue
P0731 on Hyundai by model: symptoms, diagnosis and fix
On certain 2020 Elantras the IVT (Hyundai's CVT) can store transmission codes and light the check engine lamp; Hyundai's campaign updates the transmission software and replaces the IVT when the listed codes show it may be damaged. On 2020-2023 IVT Elantras covered by bulletin 23-AT-010H, a faulty IVT oil pressure sensor can also set pressure codes, and Hyundai says to replace the whole IVT if slipping, shift shock, poor acceleration or failure to shift into gear come with them. Applies to: Certain 2020 Elantra (AD) sedans with the 2.0L MPI and IVT (service campaigns T5B and 963), plus 2020 Elantra (AD) and 2021-2023 Elantra (CN7) with the IVT for the oil pressure sensor bulletin 23-AT-010H (dated August 2023; it lists the 2021 model year onward). IVT-equipped cars only.
How to Fix
Ask a Hyundai dealer to check the VIN for open campaign 963 (it followed T5B). Under the campaign the dealer updates the TCU, reads the TCU codes in history, current and pending status, and replaces the IVT if P0730, P0731, P0741 or P0867 is present, or if the pressure learning will not complete and P1603 is stored. Outside the campaign, bulletin 23-AT-010H replaces only the oil pressure sensor when the car has codes but drives normally, and the IVT when it also slips or will not shift. Normal warranty rules apply; this is not a recall or a promise of free repair. The campaign repair itself is free for eligible VINs.
Sources for this issue (3)
P0731 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0731 mean on a Hyundai?
P0731 stands for "Gear 1 Incorrect Ratio." This code means the Transmission/Powertrain Control Module detected an incorrect gear ratio in 1st gear. The module compares input (engine/turbine) speed to output shaft speed; when the car is commanded into 1st but the calculated ratio doesn't match the expected value, P0731 sets. This points to slipping, an incorrect shift, or a hydraulic/mechanical problem rather than just an electrical fault. You may feel slipping, harsh or delayed engagement, or the transmission may go into a limited 'limp' mode. On Hyundai it is documented across 1 model: Elantra.
What are the most common causes of P0731?
The most common causes of P0731 are: Low or degraded/burnt transmission fluid, Slipping clutch packs or worn friction components, Stuck or faulty shift solenoid affecting 1st gear, Internal hydraulic leak / valve body fault, Worn or failing torque converter, Faulty input or output speed sensor, Mechanical wear (planetary gears, bands) inside the transmission. The specific cause varies by vehicle.
How much does it cost to fix P0731 on a Hyundai?
Repair costs vary widely with the root cause and Hyundai model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.