Hello my fellow 7.3 lovers,
I am having this weird issue, after getting a new hydro boost, power steering pump, and brake lamp switch put in it does not switch into OD. Three years ago I did have the transmission built, took it to my transmission guy and he came back saying it was the PCM, it's definitely not the trans, we confirmed that by running a ground wire to my torque converter solenoid (pardon my nomenclature, I'm a shade tree mechanic at best) and with his power probe it went right into overdrive after he manually commanded it. After spending $900 bucks and a few tears, I put in the new PCM yesterday and a few more tears later, still not getting into overdrive. I went ahead and talked to my mechanic and he did confirm that he didn't use a genuine ford brake lamp switch. Got a genuine ford brake switch and slapped that puppy in and I have no brake lights and it wont let me shift gears, threw my old one back in there and it let me get into gear as well as activate my brake lamps but no OD.Got a new genuine one on order just in case its defective out of the box. Does the brake lamp switch have any bearing on letting me get into overdrive? Has anyone experienced this problem in the past? Any pointers will be appreciated!

 

Are you calling the torque converter clutch locking overdrive? Overdrive is fourth gear, not the torque converter clutch. Please clarify.

 

Yes sir that would be correct, on his code reader he showed me the live data of the torque converter slip and when he sent signal, the slip dropped significantly. Pardon my inexperience.

 

What did his code reader say about codes stored in the PCM? Just changing parts at random is the most expensive way to fix this.

 

You're not wrong about that. I can't remember exactly what the code is but I think it was P0703. Tried my replacement Ford brake light switch and same thing, no lights and cant shift, aftermarket one seems to be working just fine.