Skip the auto shop - Our mechanics make house calls

Q: I'm having problems with code po740

asked by on

Hey, I have 2002 Honda Civic 1.7 that I purchased with a bad transmission, I dropped that tramission and put a used one, after I installed the transmission and ran the car check engine light came on and code was po740 torque converter solenoid. The transmission shifted perfectly fine, So I did some research I change the solenoid and ran the car the check engine light came back on, so I checked my wiring and continuity from the solenoid connector to the pcm and the continuity was good, I drain the fluid and put the dealers transmission fluid ran the car again and light came right back againg. So I took the car to a mechanic and explain everything that I did to the car, so we came to the conclusion that it was the torque converter so I dropped the transmission againg and went and got another one since it still had warranty. I installed the other transmission with a new torque converter, took the car for a spin and drove for like 3 miles and the check engine came on with the same code.

My car has 171456 miles.
My car has an automatic transmission.

A: Hi there. In order to be able to give you m...

Hi there. In order to be able to give you more exact information I would need to know whether or not the vehicle is equipped with the CVT transmission. It sounds like you have the regular transmission in your vehicle. If the solenoid is new then you either have a wiring or computer issue. I would definitely make sure that you have the right transmission in the vehicle. If the year is not the correct one then the reading from the solenoid will be incorrect. If it is the right transmission then the wiring to the transmission needs to be checked for any loose or pinched wires. If those are fine then the wiring to the computer and the resistance and the signal from the computer need to be checked. This type of problem on your vehicle is best diagnosed by a transmission specialist.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Window motor broken

If your window motor is not engaging, it is likely that the motor has gone bad. It is also possible that the switch has gone bad, unless the window also rolls down, which would indicate that the switch is likely...

Q: Torque issues

Hi there. If the slipping problem goes away when the car warms up, then it is most likely a seal or solenoid failing. As a vehicle ages, rubber seals begin to get hard and they don't seal as they should....

Q: Car no longer stays on with revving after starting

Hey there, thanks for writing in. Have a mechanic check fuel supply under these circumstances: adequate fuel pressure (fuel pump operation, clogged fuel filter, fuel pump relay and fuses, etc.). It also sounds like your battery is weak. If you...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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.