Need 545RFE Help

Hey Bob ;

The RFE series trans will set check engine light with a p0700 if there is a trans related code in TCM
,
With no engine light on problem is not being detected by TCM, problem could be with temp sensor for trans commanding L/U on and off, only way to verify is to have road test with scanner to watch data stream to see if being commanded on and off.
Temp sensor is in solenoid block assembly inside trans on top of valve body.

Other possibility is a spring problem inside front pump of trans, the tcc regulator and tcc accumulator valves are in the front pump and have a very high failure rate on higher mileage units (over 100,000 mi) good poss. of problem you are having.

Good shop and road test will be your only way to verify,

Good Luck; Lon