Q: Check engine light on and got the codes P0700 and P0731

asked by on

My check engine light came on two nights ago and I went to O'Reilly auto parts to have them give me a diagnostic test. There were two codes that showed P0700, P0731. Please help and explain what this means and possibly what the price may be.

My car has 55100 miles.
My car's transmission is unknown to me.

Diagnostic trouble code P0700 and code P0731 indicates that there is a fault in your car’s "automatic transmission control system". Although there could be a faulty "part," (such as a shift solenoid or speed sensor), there are some preliminary checks that you can perform just in case it is resolvable (or at least, "diagnosable") without the assistance of a mechanic.

For example, on Neon’s, there are reports of the heat exchanger in the radiator (the heat exchanger cools circulating transmission fluid) leaking and then letting the engine coolant mix with transmission fluid.

So you want to check and be sure that the transmission fluid is not "contaminated" with coolant because that sort of contamination could "potentially" cause these codes to set. It is also possible for a low (or even too high) transmission fluid level to cause hydraulic malfunctions that in turn will set the codes you are seeing.

So those are two things you can check right away. If those initial checks of fluid quantity and quality do not reveal anything, then you should have an expert evaluate the following mechanical and electrical components in the transmission: the transmission control module, transmission valve body, shift solenoids (typically in valve body); and a check for a possible open or short in the wiring TCM wiring harness. Typically, the problem will be found within the foregoing components without having to remove the transmission. But if not, there is an internal mechanical problem that will require further evaluation. If you would like to get a precise diagnosis, a certified professional from YourMechanic can come to your car’s location to inspect the Check Engine Light and follow through with the necessary repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Check engine light on and got the codes P0700 and P0731

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

Get a quote

What others are asking

Q: Coolant coming out the cap causing smoking when driving i dont know why

Hi there: The smoke that you're seeing is evaporated steam caused by an overheating situation. This could be caused by several mechanical issues going on inside your car such as a coolant leak, an obstruction in the coolant lines (like...

Q: My 2003 dodge neon suddely died while driving...Everything works except that it wont start

Whether or not your engine is an "interference engine" depends on which one your car has. The Neon was available with both a 2.0 ltr. and 2.4 ltr. Whether in SOHC or DOHC (single-overhead-cam or double-overhead-cam) form, the 2.0 ltr....

Q: Car sounds like it's revving in park

This concern may have illuminated the Check Engine Light as well. When fault or warning lights do illuminate, there is generally some stored fault code to go along with it. Have an experienced technician, such as one from YourMechanic, inspect...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.