DenverAirport
New member
Hey everybody. So this is in part a follow up to this thread.
Going to be detailed with this because I think some little things along the way may be important to figuring out what's going on / I may be missing something.
I had a bit over 300k miles on my trans (A340F) and it was running fairly hot, I was feeling some hard shifts, might have been a bit of slippage, and I was getting P0770 code consistently. Would show up about once a week at a minimum. I'd clear it, and it'd pop back up.
I had saved for a while for a different trans / rebuild after having done a drain and fill and found a decent amount of metal shavings (this was at about 290k miles.) Once I got the P0770 code I swapped the solenoid and the code kept showing up. I figured that meant it was time for me to replace the trans as the hard shifting had become noticeable and I drive my truck quite a bit and didn't want to be left stranded.
Luckily, I had a long trip planned and could drop it at a shop and when I returned have my truck finished. I went to Yota1 at multiple people's suggestion (including a few users here.) After talking to the owner, he suggested that the P0770 code is elusive and that it would be best for me to use a different transmission than the one with this code for the rebuild, which I agreed. So I dropped my truck off and went on my trip.
The day I flew back from my trip I went out to Yota1, picked up my truck with a reman trans, TC, and new kickdown cable, and drove it home. After 30 miles on the drive back home I got the P0770 code again. So I turned around and drove it back to the shop. They plugged in an OBD reader and we cruised around and realized the TC wasn't locking.
The owner told me this could be an issue with the ECU, he's seen this problem before. And from some of the threads I've read online that sounded right. Unfortunately they didn't have a Fed ECU so they put in a CA-emissions ECU into my truck just to test to see if the TC locked up. With the CA ECU it locked up no problem. He was thinking the ECU was the culprit. He told me I could drive the truck home with the CA ECU if I wanted or leave it there and wait for another ECU to get shipped out there. His buddy said it would probably be fine to use the Cal ECU in the short term, I called a buddy who said it's worth the risk. I got about 10 miles from the shop with the CA ECU and my truck died so I had to get it towed back to the shop....man what a day that was.
So I waited about two weeks for an ECU shipped from eBay (opted to get one with the same part number as mine, not another compatible ECU) and they put it in, tested out the truck, and the TC locked up properly. They even had an employee drive the truck home 30+ miles to see if it threw the code and it was good.
I went to pick up the truck the next day and on my drive home I got a pending code notification from my ultragauge. I went to check pending codes and saw that there were 0 pending codes, as if they had been cleared before I could check them somehow. This happened twice during my trip home (80 miles.) The next day I unplugged and plugged back in my ultragauge after starting up the truck after having had that happen. I started driving, and about 20 miles into my trip I got the pending P0770 code again.
....
So I've got a reman trans (including a reman torque converter) and a different ECU in my truck and I'm still getting the P0770 code. What else could it be? Let me know if you guys have any ideas. I've read a bunch of P0770 threads and I'm still not sure exactly as I've tested the main solutions and still haven't cleared it.
Just wanted to list the only other issues I know about in my truck right now in the case they have any relevance.
Going to be detailed with this because I think some little things along the way may be important to figuring out what's going on / I may be missing something.
I had a bit over 300k miles on my trans (A340F) and it was running fairly hot, I was feeling some hard shifts, might have been a bit of slippage, and I was getting P0770 code consistently. Would show up about once a week at a minimum. I'd clear it, and it'd pop back up.
I had saved for a while for a different trans / rebuild after having done a drain and fill and found a decent amount of metal shavings (this was at about 290k miles.) Once I got the P0770 code I swapped the solenoid and the code kept showing up. I figured that meant it was time for me to replace the trans as the hard shifting had become noticeable and I drive my truck quite a bit and didn't want to be left stranded.
Luckily, I had a long trip planned and could drop it at a shop and when I returned have my truck finished. I went to Yota1 at multiple people's suggestion (including a few users here.) After talking to the owner, he suggested that the P0770 code is elusive and that it would be best for me to use a different transmission than the one with this code for the rebuild, which I agreed. So I dropped my truck off and went on my trip.
The day I flew back from my trip I went out to Yota1, picked up my truck with a reman trans, TC, and new kickdown cable, and drove it home. After 30 miles on the drive back home I got the P0770 code again. So I turned around and drove it back to the shop. They plugged in an OBD reader and we cruised around and realized the TC wasn't locking.
The owner told me this could be an issue with the ECU, he's seen this problem before. And from some of the threads I've read online that sounded right. Unfortunately they didn't have a Fed ECU so they put in a CA-emissions ECU into my truck just to test to see if the TC locked up. With the CA ECU it locked up no problem. He was thinking the ECU was the culprit. He told me I could drive the truck home with the CA ECU if I wanted or leave it there and wait for another ECU to get shipped out there. His buddy said it would probably be fine to use the Cal ECU in the short term, I called a buddy who said it's worth the risk. I got about 10 miles from the shop with the CA ECU and my truck died so I had to get it towed back to the shop....man what a day that was.
So I waited about two weeks for an ECU shipped from eBay (opted to get one with the same part number as mine, not another compatible ECU) and they put it in, tested out the truck, and the TC locked up properly. They even had an employee drive the truck home 30+ miles to see if it threw the code and it was good.
I went to pick up the truck the next day and on my drive home I got a pending code notification from my ultragauge. I went to check pending codes and saw that there were 0 pending codes, as if they had been cleared before I could check them somehow. This happened twice during my trip home (80 miles.) The next day I unplugged and plugged back in my ultragauge after starting up the truck after having had that happen. I started driving, and about 20 miles into my trip I got the pending P0770 code again.
....
So I've got a reman trans (including a reman torque converter) and a different ECU in my truck and I'm still getting the P0770 code. What else could it be? Let me know if you guys have any ideas. I've read a bunch of P0770 threads and I'm still not sure exactly as I've tested the main solutions and still haven't cleared it.
Just wanted to list the only other issues I know about in my truck right now in the case they have any relevance.
- 1. Since having my car die using the Cali ECU, I think my IAC needs to be cleaned / replaced. My RPMs dip real quick on cold start up and then run back up.
- 2. After they did work on my trans, the shifter doesn't seem to perfectly line up with drive / reverse for the light to turn on my dash. After I set it in drive, I push my shifter up a little bit and the light turns on. I talked to the guy at Yota1 and it seems this is a quick fix. I'm assuming this isn't causing the issue but who knows maybe that's possible?
- 3. Since replacing my trans my truck overall has felt underpowered. I have half the mind to find a junker throttle body right now and put it in, because the gas pedal feels a bit stiffer than usual. That said, my truck now stays at a level RPM and I can really tell my old trans was beginning to slip. I haven't had the number of hard shifts I was regularly getting daily as well.
