I am getting a P0740 (TCC Circuit Malfunction) and P0715 (Input Turbine Speed Sensor A circuit malfunction) codes on my 2001 Intrepid R/T 3.5L.Research indicates it may be the input and output shaft speed sensors causing the problem.Where are they located?

Currently, the car will not engage at all and makes a whining noise when first put into reverse.Am l in worse trouble than l thought?

Thanks,
Rich
l tried putting the car in neutral today to move it around and the tranny is locked.Ugh! This just keeps getting worse and worse.

That is bad news, the trans control module (TCM) will force the system into limp-in mode, which is basically what u get with no power to the shift solenoids & pressure switches in the solenoids pack. You should have at least P,N,R, ans 2nd gear. If u have sufficient fluid in the trans, & still have no forward or reverse movement, than u have an internal failure, broken sun gear, carrier assembly, etc.
The Torque converter is controlled by comparing the crank sensor activity to the input speed sensor to determine TC lock up status (full or partial lock up)

to make it more simple you probably have hydraulic failure in the inside of the transmission which is causing this too happen,that either means you have a front pump bad or a inner seal has blown either way you have probably lost pressure to the valve body which engages the clutches and bands,this one will probably have to go to a shop to be diagnosed and repaired,good luck with it,

Start calling junk yards to get a new trans. l have an intrepid RT with 165000 miles on it & the original trans in it, but l changed my fluid several times. The transmissions on these vehicles r usually very tough. So there r many in the junk yards. Just make sure its out of either intrepid,300M, or Concord with a 3.5 engine NOT a 2.7. You should be able to get one for $200.00 to $500.00. AND have a shop install it for you. Which should cost about $400.00 to $600.00. Make sure they replace the TRANS COOLER at the same time. Or u can pay around $2500.00 to overhaul it.