P0736 A/T Incorrect Reverse Gear Ratio (also in forward)

The car is 2006 galant( feel kind of dumb-had this under 8th generation DUH :095:
P0736 A/T Incorrect Reverse Gear Ratio (also in forward)
car has 161+k miles, First noticed problem the other day when car would not shift into upper gear(S), at 55MPH, the rpms where a thousand high ( about 3k)

Turned car off and on re-start, problem was solved, Later wife drove car and drove into driveway so that I had to back out of drive in the AM. I applied gas and there was a pause before transmission engaged. When I shifted into drive, we where back with excessive RPMS vs. MPH ( again about a 1000 high)

Tried going manually thru the gears, fast acceleration, putting car in reverse, checking fluid level, checked to see that brakes where not dragging, Again turning car off , let it set and restart solved the immediate problem.

this morning was able to do code check and came up with P0736

Here is the CARMD.com posting:

Error Code P0736
Definition A/T Incorrect Reverse Gear Ratio
Possible Causes:

Reverse Gear is damaged or has failed

LR clutch is damaged, leaking or has failed

Problems related to the Input Speed or Output Speed sensor

Problems related to the transmission valve body
Condition For Setting The Code:

DTC P0500 not set, engine started, vehicle driven to a speed of over 3 mph with Reverse Gear commanded "on", and the PCM detected an incorrect Reverse Gear ratio during the CCM Rationality test.

Anybody got any ideas as to the real cause and a possible cure?

personaly I'd start w/ the input output sensor it tells the gears. The same sensor was makeing my second car to drop ibto first gear late and really hard but it didn't eeffect my rpm's.

Thank you, I don't know if it makes a difference, but the problem is intermittent.
I will check the senser