This article says to check Mass Air Flow (and Throttle Position Sensor and Vehicle Speed Sensor) before condemning transmission for P0743 Torque Converter Clutch Electrical if coupled with power loss. Would someone kindly explain why?
Can you provide us with a description of the problem you are experiancing? The reason to check the engine sensors is because they play a vital part in telling the transmission when to do it's shifting. I have previously unplugged my TPS sensor and didn't even get a code for about 30 min (several on/of cycles- not even sure it was related the CES light just lit). Go ahead and unplug your TPS sensor and you will quickly realize how it affects shifting. Try to go WOT from a stead gas and the transmission will stay in the same gear - not always but most of the time from my experience.) The vehicle speed sensor is critical. This is the sensor that your transmission relies on heavily for shifting. Having this go bad my my trans act crazy (never got a code). When this sensor starts failing you will see your speedo occasinally go to zero or bounce around. When it fails completely you wont have a speed reading and your transmission will refuse to shift sometimes, other it will simply stop transferring any power to the wheels - its a bid odd especially in traffic. I'm sure the MAF plays into the equation as well, probably in determining engine load and adjusting line pressure???? - not too sure on that one....
Thanks for the explanation. I had 3 error codes (all transmission related, specifically, torque converter clutch, solenoid A & solenoid C) and a complete power loss. AAMCO wanted to drop the transmission, but I decided to check this forum first.
First, I cleaned all electrical connectors in the engine compartment with compressed air and lubed with electrical contact grease. Then I cleaned MAF and erased error codes. I drove the car about 20 miles. No error codes yet. Transmission shifts normally and torque converter engages/disengages well so far.