Hey everyone I have a 2002 F150 and I recently had a local shop replace the condenser and compressor for the AC system. Ac works good but as soon as I picked up the truck I was getting a service engine light and the overdrive light was flashing. I thought it was probably just AC related but I checked the codes and I get P0743. The truck seams to run fine, I don't notice any issues with the transmission and I figure it's too much of a coincidence that it happened right after the AC was worked on. The shop owner told me the issues are not related but that he would check it out in a few days when he's not swamped. Any ideas. I figure maybe a short or something wasn't reconnected when working on the AC system. What do you think... coincidence or related? Is there something I can check that would save me from dropping it off at the shop again?

Oh one more thing, I cleared the code and the service engine light comes back on immediately after starting the truck. I don't even have to put it in gear. After about 30 seconds the overdrive light starts flashing.

 

Pretty unlikely that is is anything other than a coincidence. Can't think of anything A-C related that could cause that fault.

 

Thanks for the quick response. Since I don't notice anything wrong with the transmission when driving, and the codes pop back up as soon as I turn on the truck, any ideas?

 

Well, did you look up the fault code to see what it's squawking?

 

Oh sorry, I didn't list it. This is what code P0743 says

P0743 Ford Possible Causes

• Low or dirty transmission fluid
  
  
• Wire/circuit issue shorted to power or ground
  
  
• Failed torque converter clutch (TCC) solenoid
  
  
• Failed TCC assembly in the torque converter
  
  
• Failed PCM/ECM/EMC
  
  

Transmission fluid is full and seems clean enough. It says symptoms are

• Malfunction indicator illumination (check engine light or service engine soon light)
• Stalling when coming to a stop after cruising speeds
• Shudder on take off
• Shudder when coming to a stop

I haven't noticed any of these besides the indicator coming on with the check engine light.



I checked some fuses but everything seems okay. I originally thought this error code meant my transmission was failing but sounds more electrical in nature. I've been reading and I think most of these parts can be accessed by removing the transmission pan.

 

Have you checked the fluid level? How does the fluid look and smell?

 

Seems good to me but maybe a transmission fluid change would be a good idea anyways. I think I'll get under the truck and see if the wire harness looks okay. I don't think I want to deal with actually removing the transmission pan though. seems like a mess.

 

The only probable driving difference would be a failure of the torque converter to lock when commanded. You'd have to test the operation of the TC.