P0730

Incorrect Gear Ratio

Car Fault Codes Transmission

Severity High Get it checked soon and avoid long use.
Can you still drive? With care, short trips only
Who can fix it? Needs a specialist or dealer
Typical repair time 1 hour – 2 days
Typical cost SAR 250 to 12,000

What it means

The transmission computer compares input and output speed to calculate the actual gear ratio, then checks it against the gear it commanded. It has found a ratio that does not match any expected gear, which usually means slipping inside the transmission or a hydraulic pressure problem, without naming a specific gear.

Symptoms4

  • Engine speed rising without a matching gain in road speed (slipping).
  • Delayed or harsh engagement and shifts.
  • Transmission in limp mode.
  • Burnt smell or dark transmission fluid.

Possible causes6

  • Low, degraded or burnt transmission fluid.
  • Clogged transmission filter or weak internal pump reducing pressure.
  • A faulty pressure control or shift solenoid.
  • A valve body fault.
  • Worn clutch packs or bands.
  • A false reading from the input or output speed sensor (less common).

How to diagnose5

  1. Check the fluid level, color and smell, and look for metal or friction material in the fluid.
  2. Read all transmission codes; gear-specific, solenoid or pressure codes narrow the search.
  3. Watch input speed, output speed and commanded gear on a road test to find the gear where slipping occurs.
  4. Confirm the speed sensors are working before blaming internal parts.
  5. Have a hydraulic line pressure test done with a pressure gauge.

How to fix6

  1. Correct the fluid level with the fluid type the manufacturer specifies.
  2. Change the transmission fluid and filter if dirty and there is no major damage.
  3. Replace the faulty solenoid or speed sensor.
  4. Repair or replace the valve body if it is proven faulty.
  5. Rebuild or replace the transmission if the clutches are worn.
  6. Clear the codes, then road test through all gears and confirm the code does not return.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for low fluid or a sensor, mid-range for a solenoid or valve body, and highest when the transmission must be rebuilt.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does this code mean the transmission needs a rebuild?

Not always. Start with the fluid level and condition, the sensors and the solenoids, which are much cheaper, and only rebuild after internal damage is confirmed.

Can I drive with this code?

Carefully and for short distances only. Slipping creates heat that quickly destroys the clutches, and continued driving can turn a simple fix into a costly rebuild.

Will a fluid change help with slipping?

It helps if the fluid is low or dirty, but if it is burnt and full of friction material, there is likely internal damage that new fluid will not fix.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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