Q: P0730 99 Honda Accord

asked by on August 10, 2017

99 Honda Accord

The first signs of trouble was driving it on the highway for about 20 minutes and upon coming to a stop light and trying to accelerate the car wouldn't go. Shifted to natural and back to D4 tires spun but finally the car took off... let the car rest a few days and drove it literally around the corner to Orileys and got code "P0730" let the car rest again a few days around the block a few times. It again seemed to knock out off gear. When I got home I put the car into reverse and parked and cut the car off.. now when I put the car in ant gear the car just rolls backwards. I just purchased the car on last Friday. Not sure if it's worth stating but every light works except when it's in D4.
My car has an automatic transmission.

Transmission Fluid Service $140.08 - $502.73 Get a Quote

Hi Mercedes. This is one of those very rare error codes, but when it appears, it’s typically due to internal damage or problems inside the transmission. P0730 is the OBD-II generic code for an incorrect gear ratio detected in an automatic transmission. The ratio of a combination of engine speed and throttle position and the speed of the transmission is used to determine what gear the transmission will use when driving. If there is a problem with any gear within the transmission, then the P0730 code will appear once this ratio is calculated from the sensor data in the transmission. The repairs can be as easy as adding or flushing the transmission fluid and changing the filter - all the way to needing to replace the transmission. Since replacing transmissions are very expensive, I would recommend having a professional mechanic come to your location to complete a transmission fluid flush. This may remove the obstruction in your transmission and resolve the problem. If this works - fantastic. If not, it is probably best to start looking for a replacement vehicle - as the cost of replacing the transmission is likely more than your 99 Accord is valued.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

What does the charging system Warning Light mean in a 2012 Toyota Corolla?
The charging system Warning Light is located on the instrument panel. When this light illuminates, the vehicle’s charging system is not charging properly. Your vehicle should be serviced immediately. Tip Like all warning lights, the charging system Warning Light briefly...
Hesitation in second and third gear
I would recommend taking this to the dealership. There is a Technical Service Bulletin for the early Saab transmissions stating that there is a software update that can resolve this issue. I would have this issue taken care of sooner...
Key spinning freely in the ignition
It sounds like your ignition switch has broken. This switch has the detents in it that give you the different positions that the key goes through (e.g., Off, Accessory, On, Crank). This switch breaking explains why your key would be...
Early shift issues in 2011 BMW 328I
BMWs unfortunately become endless money pits as they age, and within those cars, they have really high-tech transmission systems. The first thing you will need to do is have a mechanic scan the car and take it on the road...
Full power but no turn over when key is turned
Hey there, I believe you are correct. The most likely cause of this issue you are having would be the ignition switch. The ignition switch is responsible for sending power from the battery to the starter when you turn the...
Donor 5 speed from '95 Nissan hard body pickup. Will it bolt up to the L18 engine in Datsun?
This is a tough case. Even if the transmission does bolt up, the difference in electronics might it difficult to retrofit to the older vehicle. The electronics must be different and there were many vacuum assisted components in earlier years...
I was driving my car. Was in 3rd gear and all of a sudden I heard a loud pop from the rear right side of my car 2002 Honda S2000
Hello - if you are able to select any gear at the transmission, but get no movement out of the vehicle (still locked up (https://www.yourmechanic.com/question/wheels-locked-up)), I would suspect a broken axle or wheel hub/bearing assembly that has failed in a...
steering column shaft is hitting the wall to the left and right when turning.
Hi there. Check the locking pin to the steering column shaft and make sure that it is locking to the input shaft to the rack and pinion gear set. If the lock is engaged and the shaft is coming off...
I let my uncle change my pads and rotors and now everytime i press the brake all i get is an air sound scared to drive
Usually a hissing noise when you hit the brakes involves the vacuum brake booster. But it seems unlikely that working on the brakes should effect this component. Changing brake pads and rotors is a pretty straightforward job, even on a...

Related articles

A Buyer's Guide to the 2012 Honda Crosstour
There There could be a number of reasons an SUV isn’t right for you: the price, the size, their mpg, etc. However, there could also be a number of reasons you’d really like to have some extra space. If that’s...
The Best Used Cars to Buy If You Have Kids
Once Once you have kids, the kind of car you have becomes very important. Suddenly, the amount of space, entertainment features, reliability, safety, and easy to clean interior become the top priorities. Here’s a list of vehicles meant to satisfy...
The 5 Safest Used Cars You Can Buy For Under $20,000
The Subaru Legacy, Honda Accord, Ford Fusion, Chevy Volt, and the Volvo XC60 are five of the overall safest used cars you can buy for under $20,000.