4r70w OD problem

fordpatriot · #1 (**permalink**) 07-04-2009, 08:05 AM

Good day everyone, new to the post here and usually do not require assistance repairing my vehicles but I have a 94 f-150 2wd with the 4r70w trans in it and something new is going on that I have never seen before. Tooling down the road the tranny will come out of overdrive and into 3rd and then shift right back into od again. There is no reason for this as I am not accelerating or pulling a hill or anything. Just hanging out at 1800 or 2000 r's and boom it happens. Od switch is working fine and no codes on the switch. Any thoughts out there? Trans has been serviced and shifts good. Thanks

Mark Kovalsky · #2 (**permalink**) 07-04-2009, 08:50 AM

It's the Transmission Range Sensor (TRS.) That's the sensor on the driver's side of the trans where the shift cable attaches. It has a wiring harness plugged into it. Get a new one and install it. Yours is dying.

fordpatriot · #3 (**permalink**) 07-04-2009, 08:59 AM

Thank you for the info. I have had suggested it was the brake switch but did not feel that was the answer as I do not believe if you tap your brakes it should come out of OD. Plus it would deactivate the cruise control all the time. I will check the harness and connections and if all is good, change the sensor. Do you know if this is a dealer only part, or does after market sell them?