code P0742 and PO657 wont clear transmission stuck in limp mode

[amalia]

anyone have this issue as i can clear these code with hand held scanner

[dabangsta]

Clearing the codes only works if the issue is fixed, so whatever is causing the 2 faults needs fixed.

 

[Billiam]

I agree, just clearing them will not resolve the issue and they will be back. I cleared all the codes, but they came back in short period of time (I did it to see if it was just an anomaly when they first showed up).  My wife's 2019 Edge is in the shop right now for the 4th time with just the transmission issues (we've had the purge valve issue and other emissions issues). They have no clue what's causing it, and it's stumped the Ford engineers. I don't recall all the different codes it has thrown, but limp mode was mentioned and was part of it on the second round that it was in for (or it was the third). All I can say is good luck, but the 2019 transmissions are not one of Fords finest, might end up being the worst in my book. 

[amalia]

I did replace the valve body and shift module assembly 8 months ago and it still didnt clear the codes so i did the same troubleshooting per for charts to hunt down and open wires but none were found....so the thext thing i did was replacece the original battery and all problems went away for 8 plus months....i took AGM battery back to napa and its good then i charged it at home with agm new style charger and it took 100% charge. started at 60% and took 2 days to reach 100%. i treid to start it up but still dang limp mode issue is there. So today i will re read all my notes and see what other trouble shooting i can find. PCM/ECU might be bad and flagshift 1 computers has a repaired one for 300.00 bucks. will try the freeze the computer with freon and see if that fixes the issue. this is the 3rd time this exact issue has happened and only in hot summer 100F where having in texas for past 20 days. might be internal ecu/pcm thats breaking down. Who knows....so now im driving my 1963 amc rambler everyday and its just old and reliable as aways. no sensor/computer crap to deal with.....have it for 27 yrs now and still a great car.Go figure. Dealer tech is stumped also. 

[amalia]

Update on the transmission PO657 and PO742 code issue this hot fort worth texas sunday. Thank god for cold beer.....I used my notes from last time i did all this repairing and tested the PCM 12 vdc power to transmission shift solenoid module.....which i replaced new from dealer.....Still got a good year left on warranty.....last time the same exact codes led to replacing all that.....go it programmed also.....so the trans plug 168 pin 15 is to supply constant voltage to shift module when key is on ...the test 12vdc probe at that 15 connector will light up for a nano second then turn off......still same problem .....then i put everything back together and started it up and all good for now and trans is working good...Im now thinking the PCM/ECU is bad. maybe the internal pcm  supply 12 vdc to trans is hanging up....thats what my ford trouble shooting tree schematic is telling me....ill drive it to work tommorow and see what happens......flagship has a pcm/ecu for 159.00 on sale .....ill get it 

[amalia]

update on transmission problem with those codes P0657 and P0742. the cable harness going from PCM to Transmission was bad. on the transmission shift module main plug was checked out 3x by doing a continuity test and all was good but when plugged in transmission connector if you wigged that plug i now can hear the transmission shift solenoids actuate. Problem solved and i got that new harness from the dealer for 275.00 and took 6 hours to remove and replace. I waited a month driving car and problem is gone. I wiggled the new connector/harness at same area, and all is good. Finally, this very intermittent problem is gone. 

[MEwhyeventry]

That’s awesome! Happy you figured it out. Congrats!