What Does Engine Code P0730 Mean?

If your car is showing the P0730 engine code, then an incorrect gear ratio has been detected in the automatic transmission.
Written by Rob Shapiro
Reviewed by Melanie Reiff
A P0730 engine code is a diagnostic trouble code (DTC) that relates to an incorrect gear ratio that is detected in the car’s automatic transmission. This engine code can range from a minor issue to a more serious one, as the transmission determines what gear to use by the ratio of engine speed, throttle position, and the speed of transmission.
DTCs identify specific issues within the vital systems of a car. They can let you know if there are issues with your transmission or catalytic converter and notify you that your car might not be road safe. 
Car insurance
comparison app
is sharing all its DTC knowledge with you while also helping you save money on car insurance. This helpful guide explores the P0730 engine code so that you understand what repairs might cost, how serious it is, and what this DTC actually means.
Jerry sends free alerts to keep your car up-to-date so you can avoid costly repairs
* checking your rate won’t affect your credit score
Get ahead of my car maintenance
* checking your rate won’t affect your credit score

What does the engine code P0730 mean?

Definition: Incorrect gear ratio
The P0730 engine code identifies that something is wrong with a vehicle’s automatic transmission. Any problem detected within the transmission will trigger this engine code after the ratio is calculated from the transmission’s sensor data. 

How much will it cost to fix?

It’s hard to say how much it will cost to repair the issue related to this engine code. When budgeting, consider that the average auto shop will charge between $75 and $150 per hour. It should take about one hour to diagnose

What can cause the P0730 engine code?

Possible causes behind engine code P0730 engine code include:
  • Low level of
    transmission fluid
  • The transmission fluid is dirty
  • An issue with the
    shift solenoids
  • Transmission mechanical issues
  • The transmission hydraulic control circuit is malfunctioning
  • A broken mechanical component within the transmission
  • An issue with the transmission control module
The transmission control module will detect this problem when the transmission attempts to shift to a lower gear than intended.

Common symptoms of the P0730 engine code

The P0730 engine code may trigger these two symptoms:

How serious is the P0730 engine code?

There is a wide range of severity for this engine code. Regardless, since it concerns your transmission, you should inspect and perform the repairs or visit your mechanic as soon as possible. 
The actual severity depends on the abnormality in your transmission. It’s important to note that even minor issues with your transmission will trigger this engine code.
In some cases, the engine code will be resolved by a simple reset. 
Key Takeaway: A P0730 engine code can be a minor fix or a serious problem. If your car shows a P0730, it’s best to check it out right away.

Can I fix the P0730 engine code myself?

If you are keen to do the repairs yourself, start by visually inspecting the related wiring harness and connectors. You should keep an eye out for any damaged components or connector pins that are broken, corroded, bent, or pushed out.
Typical repairs for the P0730 engine code may include:
  • Repair or replace any wires that appear to be damaged or corroded in and around the transmission control module.
  • If something is wrong with the shift solenoids, the pump, or the torque converter, then you will have to remove the transmission to repair it.
  • After you’ve completed the repairs, replace the transmission and test it to make sure it works without any DTCs.

Pay less for your car insurance

, a
trustworthy licensed insurance broker app
, will find the right coverage for you at the most affordable rate. We shop from 55+ top insurance companies and will take care of you every step of the way.
“When using
, I just put in a bit of information, and they found lots of different quotes for me. I was paying $305 a month for 2 brand-new cars, but now I’m paying $150 a month for both with full coverage!” —Robin U.
Haven’t shopped for insurance in the last six months? There might be hundreds $$$ in savings waiting for you.
Judith switched to Progressive
icon savingsSaved $725 annually
Alexander switched to Travelers
icon savingsSaved $834 annually
Annie switched to Nationwide
icon savingsSaved $668 annually
Estimate your repair costs for free with GarageGuard™
Simplify your car maintenance with Jerry.
Try GarageGuard™

Easiest way to compare and buy car insurance

No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
Find insurance savings