1999 f150 4x4 4.6 4r70 with body swap from 2003 f150 4x2 5.4 4r100. Everything works except trans is stuck in limp mode (won't shift out of 2nd) and speedo doesnt work. Been diagnosing wiring for what seems like forever. Most recent thing I've been doing is checking voltage signals for all the speed sensors and all seem to be good. Everything is fine mechanically and even had transmission solenoids replaced (waste of money). Throwing codes for shift solenoid a and shift solenoid b. If anyone knows anything that I don't or anything else to look into it would be greatly appreciated.

 

which PCM did you use?

 

Had the 1999 pcm in at first, took it to ford dealer for flashing, they said pcm was no good, so put the other one in and all was fine until I had it at another mechanic to get looked at, they said that this PCM was no good, they talked me into getting another different pcm put in so now it has one that they got from a wrecker.

 

Bump

 

You checked fuses? And check harness where it drops down by the passenger cat, known chaffing spot

 

Checked all fuses and all relays. Harness is not chafing either. Good Signals on all speed sensors going into the pcm, now have to check if signal is leaving the pcm.

 

2wd 2003 f150 with 4r100 non svt? what trim package has that?

 

Very rare 7700 package.

 

Because so much was done and there are SO many variables that we don't know how were addressed, this is going to be about impossible to diagnose online.

I would start by getting the wiring diagrams with computer pinouts and check to see if there is continuity from the PCM to the transmission on all the wires to the individual components. With the computer disconnected you can check for the proper resistances. If you are careful you can even apply voltage to the solenoids through the computer connector and harness to see if they work.

D

 

2003 f150 Lariat 2wd with 7700 package

 

I have all the wiring diagrams and pinouts and checked for pin differences between the two and any differences between them have nothing to do with the transmission. I have checked a few wires for continuity but have mainly been focusing on getting the speedometer sorted out in hopes that that could be the reason the transmission is not shifting.

How would I apply voltage to test the solenoids? I am assuming that they are fine because the last shop I had it at replaced the solenoids.

 

If the speedo doesn't work it could be the VSS/OSS circuits, which definitely affects transmission shifting too.

 

oh nice, didn't know the 7700 was available in that late of years, thanks for the info

 

bingo!

D