geoff17

Ok sorry if this is a newb question but this is the first auto car I've ever put together, I always was 6 spd before so I'm clueless in this area. Quick background I swapped in an LQ4 4L80 into a 93 Foxbody. Everything is good except that the trans doesn't shift, seems like it starts in 2nd, but after a little driving I think I got first now too. But it still won't go to 3rd or 4th. What do I need to look for? I called my tuner and he said it shouldn't be a tune issue since the ecm was already set up to run an 80e. So what direction do I need to start looking to figure out what my problem is?
Thanks

jt76

iTrader: (10)

check the fluid?

geoff17

Yup, it was very slightly over filled before I drove it I figured it would use a little extra and then I'd need to add some after since it hadn't been driven yet and was bone dry before since it sat a long time before I installed it. Then forgot to check it after I'll do that today. But can fluid level cause it not to shift into the higher gears?

Jake's Performance

iTrader: (2)

A 4L80E starting in 2nd and not shifting (default is 2nd) is likely no power on the E pin at the main trans connector.

geoff17

Ok how I do I test this? Do I unplug the big round connector and probe a certain pin with key in the on position and look for 12v? If so which pin? If not how do I test this?

Thanks for the replies btw

Jake's Performance

iTrader: (2)

Correct, the "E" pin as previously stated.

geoff17

Great thanks, I'll try to make some time to test this out tomorrow. Didn't get a chance to even mess with the car at all tonight.

geoff17

Well I have 12v at the "E" pin and still starts in 2nd and doesn't shift. Where do I look next? I may drive to the auto store to read it and maybe there is a code in there but I don't like the idea of driving around in 2nd all the way there, bad idea?

CarolinaTA

iTrader: (6)

check the pink wire under the car on the 20 way connector under the car at the tranny, im having the same problem codes arelisted in my thread, solenoids a and b electrical, having a friend lookat it Sunday because im outta ideas.

Jake's Performance

iTrader: (2)

The pin wire is the E in already suggested and checked.

It gets more complicated to diagnose. Command the solenoids with a scanner and check for continuity to ground on wires A and B.

geoff17

Correct, the E pin was a pink wire near the edge of the round connector to the side of the trans and it had 12v with the key in the on position. I don't have a scanner but I have a friend with hptuners is this something that can be done with hptuners (commanding the solenoids)? And sorry but I'm not great with wiring but are you wanting me to test continuity between A and B on that round connector during the time where we command the solenoids?

geoff17

Another thing I had somone mention to me yesterday is that if the brake switch is wired incorrectly it can put the trans in limp mode. What is the proper way to wire up the brake switch? Apparently there are 2 ways to do this.

geoff17

Ok so I pulled the codes today and the trans had 2 codes for it P0753 and P0758 which were shift solenoids A and B. So where should I start looking now and should I still address the way my brake switch is wired up, can that cause any of this?

geoff17

So any ideas anyone? Should I start by looking into the brake switch wiring or pulling the pan and looking at the shift solenoids? How can I test the shift solenoids?

geoff17

Ok so I got some testing done, narrowing some things done. The internal harness in the trans is in working order and the solenoids ohm out correctly, both between 21-22. I also can get the solenoids to "click" Can the solenoids be bad and still ohm out correctly and click but just be seized up or something and not actually moving?

maddoglou454

We use an external full manual box for the 4L80Es. They work excellent run 12 V to red wire, and ground the brown wire it will activate lockup. Of course, run it on a toggle switch.

You can call us and talk to a live person. Up until 10 PM Eastern standard time , Monday through Sunday.

Thank You,
"Mad Dog" Lou

Mad Dog Transmissions
Phone 770-781-0949
Fax 770-781-0969 maddoglou454@aol.com