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P0730: Incorrect Gear Ratio

P0730 reports a wrong transmission ratio without assigning it to a gear. Two uses are documented. Older Aisin-type automatics (a 2006 GM table, Saab's 9-5 of 2002) set it when fourth or fifth gear shows the ratio of third – a shift solenoid (Saab: S3) is not switching; GM lights the MIL at once, Saab enters limp mode. GM's continuously variable transmissions of 2023 and 2025 use it when the pulleys do not reach the commanded variator ratio – the belt or chain slips or clamping pressure is too low – after one trip. Ford and newer GM step automatics use gear-specific or clutch valve codes instead. Check fluid level and condition first.

High severity. Can I keep driving?Continuing is not recommended: if the transmission slips, it can overheat, break, and leave you without drive power while moving. If you have no other option, drive very gently and only a short distance, or use a tow truck.

Symptoms

  • Slipping, engine speed rises without drive
  • Wrong gear or missing upper gears, limp mode
  • Check engine light (GM) or transmission warning
  • CVT: judder, weak acceleration

Most likely causes

  • Fluid level or quality (CVT fluid or ATF)
  • Shift solenoid or pressure control valve sticking or faulty
  • Clutch or brake wear, or worn variator belt, chain or pulleys
  • Faulty speed sensor signal

What to check, in order

Start with the simplest. You can tick off each step.

Good to know

  • Repair difficulty: hard
  • It can trigger limp mode.
  • It affects emissions.

What each character of P0730 means

  • P: Powertrain: engine and transmission
  • 0: Generic code: same on every make
  • 7: Transmission
  • 30: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0730?

Continuing is not recommended: if the transmission slips, it can overheat, break, and leave you without drive power while moving. If you have no other option, drive very gently and only a short distance, or use a tow truck.

What causes code P0730?

The most common causes are: fluid level or quality (CVT fluid or ATF); shift solenoid or pressure control valve sticking or faulty; clutch or brake wear, or worn variator belt, chain or pulleys.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.