I've noticed of late my 01 ES 3.2 has only been getting about 16 mpg & my light is on. I had auto zone check & it pulled up P0740, P0700, & P0601. The car seems to run & drive ok, but the mileage concerns me. Help!!

 

sounds to me as tho your PCM is on its way out. this could be causing the P0700/0740 codes, both being tranny related. 0700-general fault in trans. 0740-traction control circuit malfunction (torque converter lock up issues).

both are serious and costly issues. you could be looking at a new/reman trans.
also a new pcm, which if you have the sentry key (grey headed key), you could be looking at a costly dealer replacement due to programing of the keys.
do some research and get the trans diagnosed quick. have heard the trans failure can lock up the front wheels completely. pretty scary...

 

I was afraid of something like that. So, in other words, because of the sentry key, I couldn't just pop in another pcm? But if there is something with the tranny to boot, it's time for it to go........

 

you could try to disconnect the negative terminal (for a few minutes) of the battery jump post. this will clear the codes from the pcm. reconnect and then take it for a spin to see if the codes return. it could simply be a glitch in the pcm which caused all codes.

you could find a used pcm of the same year--not sure what other years are compatible--and see if the dealer would/could reprogram the used pcm to your car.

 

I've been intending to take the cable off and try that and hope. The car seems to be running and driving fine. The only thing I've noticed is a decrease in the mpg. It's a 3.2 with 64k.

 

i would try it sooner rather than later. and preferably close to home just in case. after you disconnect and reset the codes, give it a drive and post back. good luck...