Anonymous asked in Cars & TransportationCar MakesAcura · 10 years ago

What are the possible affected components in a '02 Acura MDX when you get a code P0740 (TCCC Circuit Malfunc)?

Hi. Last summer, my check engine indicator lit up and I took it to the dealership. They found Code P0740. They noted on my receipt that they found the transmission to be failing and recommended it to be replaced. I didn't notice anything wrong in the way my car was running. No noises, goes into reverse when I put it on reverse, wasn't slipping, it was running great, actually. But I know nothing about cars and when I was told that my transmission needed replacing, I had it replaced. Looking at my receipt, it appears that they also changed the ECU. The diagnosis costed me $70.04, and the transmission and ECU, $5,421.90. (Please don't scream). I was just talking to my friend about it and he told me that the only possible affected components with that code are 1) hydraulic control system; 2) torque converter, and 3) transaxle. He also said that failure of any of these three components would render the car undriveable. But my car was running just fine. He also said that the transmission is irrelevant, and the ECU is irrelevant. Can a mechanic please confirm all that? Thanks guys!

1 Answer

  • 10 years ago
    Favorite Answer

    Yes, he is correct... Alot of times an ECU or ECM will give FALSE codes.. the P0740 is mainly targeted to Transmission Torque converter Failure... Now, since this is your car, you drive it and would know if the transmission is acting funny. I cant believe they would replace and charge you a new transmission without even a test drive or even a proper diagnosis.. if i were you i'd be filing a Law suit!!!

    Generally when an ECU is determined to be giving false trouble codes, most would replace with new before actually diagnosing whats wrong to begin with... I think you have a good Lawsuit on your hands...

    Just because you scan codes and get a trouble code, you dont stop there and replace the part.. for your transmission for example, proper diagnoses of your torque converter function should have been done... They should have test drove it and confirm it shifts properly, go back and erase the codes and see if they come back..

    Im a certified ASE mechanic and i am telling you to seek legal action against the garage that did your transmission and ECU replacement!!

    Source(s): ASE certified Mechanic 12 years.
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