OBD Codes List

Diagnostic reference · P0730

P0730

Incorrect Gear Ratio

System
Transmission (P code)
Lamp
Check Engine Light
Category
Powertrain - Transmission

What it means

P0730 means Incorrect Gear Ratio.

Check these first

  • Worn clutches or bands from slipping
  • Low or burnt transmission fluid
  • Stuck or faulty shift solenoid
  • Failing torque converter
  • Internal transmission damage

What to do next

  1. Check transmission fluid level, color, and smell first
  2. Watch commanded vs actual gear and gear ratios on a scan tool
  3. Confirm the transmission slips or flares on a test drive
  4. Test solenoids and pressures with a scan tool
  5. Rebuild or replace the transmission if internal failure is confirmed

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Updated

Generic SAE J2012 definition. Last updated 2026-08-30.