Why don't they know about P1759 and P1757?

Discussion topics related to the radiator and transmission failures in all Nissan trucks, education of the public on this issue, and attempts to force Nissan to start a recall.

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Spartacus
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Why don't they know about P1759 and P1757?

Postby Spartacus » Wed Nov 02, 2016 11:50 am

My 2005 Pathfinder (160,000 miles original owner) went into "Safe" mode on the trans the other day (it's stuck in 3rd gear).

It starts in first, goes to second then stays in 3rd for the rest of the trip even when I slow or come to a stop.

Codes showing are P1759 and P1757 (full disclosure, they are also showing P0420 and P0430 (Catalyst issue) also but that I don't think is related.

I did a major service about 2 months ago then drove it to Oklahoma and back from California just fine.

After reading this and other forums it seems that it is most likely a TCM issue. I did the radiator bypass at about 30,000 miles.

I have taken it to 3 different mechanics and all of them said I will most likely need an entirely new trany. Each mechanic verified that there is no debris in the pan at all. They all want to charge me $3000 - $4000 for the work.

None of them seem to know about the TCM issue. As a matter of fact when I brought it up to one of them they told me, "I'll do what you want to the tranny but when it doesn't work you still have to pay for it."

When I ask why they think it is a full trany replacement none have any answers other than "the codes say you have a problem but we can't tell you exactly what it is until we take apart the transmission."

So this begs the questions,

1) how often is it a TCM issue when those codes show up?
2) could it be something else?
3) is there anyway of testing to verify it is the TCM without just replacing it?
4) what am I missing, why don't any mechanics seem to know about this?


On a side note if any one has done this recently with a mechanic (I have no means to do it myself) how much did you pay?

Thanks in advance.


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smj999smj
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Postby smj999smj » Wed Nov 02, 2016 9:05 pm

Nissan did release a technical service bulletin (NTB10-003a) for the P1759 DTCl. Basically it says to check the TCU power supply and ground circuit. If that's good, then check the TCU and its harness connector for bent or damaged pins. If those are okay, then replace the TCU.
Some Titans and Armadas have had corrosion issues with water getting into the connector on top of the trans from the valve body, so it may be worth seeing if the Pathfinder has a similar setup. Otherwise, most of the P1759/P1757 problems have been fixed by replacing the TCU/Valve body assembly. I have heard or remanufactured valve bodies being available for the RE5R05A transmissions, so that may be something looking into. It would be much cheaper than replacing the entire transmission.

Spartacus
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Joined: Wed Nov 02, 2016 11:27 am

Postby Spartacus » Mon Nov 07, 2016 9:55 am

Thanks!!!

Spartacus
Posts: 3
Joined: Wed Nov 02, 2016 11:27 am

Postby Spartacus » Mon Nov 07, 2016 4:51 pm

So, my mechanic took it all apart and tested all the leads on the TCM. Said everything was working perfectly.

With these codes and situation, is there any other likely diagnosis?


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