Nissan Frontier, code P1776

[AZhitman]

So, our little '98 Frontier is throwing a P1776 code. From my research, it's a solenoid in the transmission valve body, Found the one that was sticking and replaced it. No CEL for a while, then it came back.

Looks like there's a TSB on it: TSB #NTB00093, NHTSA ID #615855

Anyone else dealt with this? I need to get this thing through emissions, and I'm a little tired of throwing parts at it.

[PapaSmurf2k3]

Is the VIN between 1N6DD25S11C327076 and 1N6DD25S51C335441?

[AZhitman]

Nope.

1N6DD26S3WC347675

[PapaSmurf2k3]

That TSB supposedly only applies to that VIN range (vehicles built between September 22 and October 12, 2000).

That being said, if someone at some point installed the wrong speed sensor assembly, it could be causing your issue. The TSB states that if the pinion gear is pink, the gear is correct. If it is green, it is wrong.
I guess it could also be cracked or something
The part number it gives is 32743-36F20.

[AZhitman]

I'll check it out.

This friggin' truck is giving me a damn migraine. Why the hell a damn trans solenoid code should keep it from passing emissions is beyond me.

Also wondering if maybe the TCU ground might not be adequate... which means I have some tracking to do. The solenoids pop when 12v is applied, but that doesn't mean the TCU is sending the full 12v.

[PapaSmurf2k3]

Swap in a manual?

Is it actually shifting erratically, or is it just a CEL?

[AZhitman]

Shifts perfectly, runs great.

Would love to swap in a manual, but it's not in the budget right now, and it's gotta get through emissions pronto (tags are expired).

[Towncivilian]

Have you tried to measure the resistance of the solenoid valve following the instructions on page EC-400 of the FSM? I know you replaced the part recently, but it doesn't hurt to check (well, as long as the harness is easy to get to, heh). Did you use an OEM replacement part?

[AZhitman]

OEM replacement part, yep. Will check resistance in a sec.

[SteveTheTech]

Pardon the delay boss man. This is not a good code.

You have a Torque Converter solenoid code, as you mentioned. The logic for this code means the TCM is commanding the torque converter to engage but the output signals are not registering the engagement of the "overdrive" function of your transmission. The computers simple logic can only assume the solenoid is not working, but in most cases it is. You could watch it in a data stream, but if you replaced the solenoid and it did not immediately set a light you could almost assume the electrical inputs are good. The electrical connections on that trans are wicked simple, there are no CAN lines and you do not live in an area that I would suspect wire damage. Plus for that you would probably have other problems.

Real Talk,
A torque converter would be the easy route but if there is a problem with with pilot pressure circuit a new converter wouldn't do anything. If it were mine I would consider a JY or reman trans because, I'm cheap, impatient, and lazy.

What's the fluid look like?
Does it have any issues going into lockup on the highway? Any judder?

Feel free to contact me directly if I can help.

[AZhitman]

No worries. I suspected as much. So, we went through the FSM procedures for checking everything (absent the stuff you have to use a line pressure tester and Consult for). Dropped the pan, dropped the valve body, etc. Fluid looked good. Not bright red/clear, but not brown either. Inside of the trans looked good, minimal "goo" on the pan magnet.

Reassembled, and now it doesn't have reverse. Oh well, I figured we'd be R-squaring a trans anyway. Bleh.

The frustrating thing with this truck is I don't think we intend to keep it. My son was driving it, but has "seen the light" and realizes he hates AT almost as much as we do.

I think we'll replace the trans and put it on the market. Thanks Steve and others... you guys rock.

[AZhitman]

After further diagnosis by the best trans shop in the city and the Nissan dealer, we don't know any more than we did.

Trans is gonna be $2200 minimum, and that's almost what I paid for the truck.

I'm gonna put it on the market with the CEL and take the hit on the price. Dammit.