P0700 on a Hyundai: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

You can usually drive a Hyundai short-term with P0700, but stop if the transmission slips or shifts harshly.

What P0700 means on a Hyundai

On a Hyundai, P0700 is the transmission control module flagging a stored fault to the engine computer. The specific problem is saved as a separate code in the TCM that a basic OBD2 reader cannot see. Hyundai automatics manage shifting through solenoids, so the code usually points to the transmission control system.

Is P0700 common on Hyundais?

P0700 shows up on Hyundais with automatic transmissions, especially Elantras, Sonatas, and Santa Fes with higher mileage. Faulty shift solenoids, low fluid, and speed sensor failures are common triggers. Hyundai recommends regular transmission fluid service to keep the TCM working properly.

Commonly reported on: Elantra, Sonata, Santa Fe, Tucson.

Symptoms

Check engine light on
Harsh or delayed shifts
Transmission warning light or limp mode
Sometimes no drivability change at all

Common causes

most common: Faulty shift solenoid
common: Low or dirty transmission fluid
common: Failing speed sensor
less common: Faulty TCM or wiring

How to fix it

Fix	DIY?	Typical cost
Read the stored transmission code with a professional scan tool	Mechanic	$80–150
Change the transmission fluid and filter	Yes	$100–250
Replace the faulty solenoid	Mechanic	$200–600
Replace the speed sensor or repair wiring	Mechanic	$120–400