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Discussion Starter · #1 ·
I have a 2010 GTR with 43,000 miles, cobb A/P, 4" exhaust/y-pipe, and Top Secret Intake and up until a month ago the car was driving without any issues at all. All of a sudden I hit limp mode one day driving around, I pulled the code and saw it was P0777. I did some research on here and talked to a few specialists and many people said it was often linked to dirty fluid which I was due for a fluid change though it was not that bad. I picked up some fluid on very short notice from Tony Palo @ T1. I changed the fluid, drove the car around for 20 minutes and back into limp mode we go with the same exact code. Since P0777 is a solenoid code, the next thing I did was remove the valve body from the transmission and clean all the solenoids individually, I put it back in. Drove fine for 20 minutes, back into limp mode still have code P0777. I figured maybe the solenoid is just faulty, so I installed a new valve body courtesy of Jack @ Jack's Transmissions and still getting code P0777.

When my car is not in limp mode, it drives perfect, shifts through every gear perfectly and drives just like it always has and should. I started looking for a trend to see what is causing the car to go into limp mode and realized that every time transmission temperatures exceed 165 degrees Fahrenheit the car goes into limp mode, if the temprature falls below 165 degrees faranheit, the car goes out of limp mode. I'm beyond frustrated, I can't find anything damaged in my transmission and I've been in the transmission 4 times. I tried taking it to a local Nissan dealership as well who pretty much concluded I wasn't going to be covered by warranty because of my non OE fluid and lack of fluid change service history from the previous owner.

Does anyone have any idea what is causing the problem? I'm tired of getting into the tranny, changing parts, fluids, and not making any progress at all. I'm getting the same code consistently, same problem and I don't see any damage to the transmission. My assumption is that at 165 degrees transmission temps something is supposed to happen and it's not happening and the car is going into limp mode.

Any help or previous experience is greatly appreciated, I just want to be able to drive my car without it throwing itself into limp mode for any distance.

In Summary:

Code P0777, car goes into limp mode.

In limp mode I only have gears 2,4,6.

Transmission temprature going above 165 degrees Fahrenheit is triggering the limp mode.

When car is not in limp mode, drives perfect.
 

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Hi Rosso, I had the exact code and it happened at the same temps. P0777 is a newer trans code, what LC are you running?. I had LC4 and it gave me the p0777 code. I uninstalled my Cobb (returned it back to standard) and it gave me code p0846, same code basically. The problem was clutch sensor B. If you are slipping gears when the code is not present then it's more likely to be clutch seals. If not then the seals would be okay in my opinion. There are three sensors in the trans, x1 in the valve body and x2 in the front TCM module/oil pump. The two in the TCM module sends signals for both clutch A and B. I removed my trans and replaced the two. Also you might want to check your wiring behind your rear seat (TCM module) the Yellow wire is for the clutch B + which mine was worn a little bit. Soldering it works a treat. I have not had any problems with my car since..... Good luck

Pree
 

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Discussion Starter · #5 ·
Sorry to revive an old thread but in case anyone had the same issue I wanted to give some light at the end of the tunnel.

Just wanted to update the thread since I got a few PM's on others having the same issue.

I ended up getting a new front cover from Jack over @ Jacks Transmissions and it resolved the problem, the failure is likely a clutch failure.
 

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I am having the same problem and code, opened up the gbox, cleaned everything but still not working :( 165F goes into limp, even in Parking, wasnt even able to align clutches with Ecutek

T800 linney clutches, circlips, baskets, trans pan
2012 DBA BE

The code appeared first time after some track driving, and got into limp .. again after 2-3 launches and now goes into limp mode at normal driving
 

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I just got the P0777 code, same situation. After reaching 165deg temp on the transmission, limp mode kicks in. No slipping clutch (I feel no degradation in performance at all). Run smoothly and perfectly as it would below 165deg temp.

Will removing just the dtc code using ecu tek cure it?

Details:
2012 BE, bone stock just mid pipe, zero history of check engine or any dtc codes whatsoever . 66k miles, all maintenance fluids up to date. Been reliable for almost 5 years since I owned it.
 

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Shaolin Shadowboxer
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It’s likely failed clutch pressure sensors or clutch seals. If you had a way to do a TCU log to see what the sensor voltages are it would help diagnosing the issue. Either way the trans has to come down to access the sensors or basket in the front of the transmission.
 

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Yep i am in the same boat even after numerous professional wirings of the dodson module (and removal) and installation of the plug and play Dodson sensors, same code, same conditions as the others on this thread. Is it time for a Tesla??
 

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Shaolin Shadowboxer
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When my problem arose I replaced my clutch seals and it ended up being bad Dodson sensors. I had no module. I went through the sensors reading normal until they warmed up.
 

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Shaolin Shadowboxer
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These were clutch a and b pressure sensors. I replaced all three after narrowing it down. I posted a thread with the data of showing the sensors’ erratic voltage somewhere. I believe as these cars age we will see more of this.
 

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Shaolin Shadowboxer
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Yeah while you’re in there you should have the clutch seals replaced as well. That’s what we thought was the issue was primarily. Turns out it was the OEM sensors and then the first batch and second batch of Dodson sensors. The third time I pulled the trans and replaced them with the ones Shep said we’re not from Dodson. Keep in mind the first two sets of Dodson sensors I got from him. He really looked out and took care of me.
 

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Yeah while you’re in there you should have the clutch seals replaced as well. That’s what we thought was the issue was primarily. Turns out it was the OEM sensors and then the first batch and second batch of Dodson sensors. The third time I pulled the trans and replaced them with the ones Shep said we’re not from Dodson. Keep in mind the first two sets of Dodson sensors I got from him. He really looked out and took care of me.
Which brand of sensors did Shep end up putting in there? Last time I asked him recently he said Dodson was still what he used. I got the module ones first that Dodson had issues with then had the plug and play (newer version) put in and am still getting the P0777 code when the trans heats up to above 83 degrees celsius. The rest of the time the car drives fine but once it hits the magic number in the trans then something is putting it limp mode with 2-4-6 gearset only.
 

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Shaolin Shadowboxer
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He didn’t divulge the brand of sensors… only that they were not Dodson or SSP and that they needed to be scaled. Also it was myself that dropped the trans and replaced the sensors. Car has been running good ever since. He confirmed one was faulty when he got them back measuring 144mv.

What does the sensor voltage show when the trans reaches temp? You need to log the trans. Keep in mind that I’ve noticed from a cold start and cleared ECU/TCM, my car would shift normally with a faulty sensor until it reached 160*F. I confirmed via data logging when I was trying to figure out what was happening.
 

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He didn’t divulge the brand of sensors… only that they were not Dodson or SSP and that they needed to be scaled. Also it was myself that dropped the trans and replaced the sensors. Car has been running good ever since. He confirmed one was faulty when he got them back measuring 144mv.

What does the sensor voltage show when the trans reaches temp? You need to log the trans. Keep in mind that I’ve noticed from a cold start and cleared ECU/TCM, my car would shift normally with a faulty sensor until it reached 160*F. I confirmed via data logging when I was trying to figure out what was happening.
My voltage starts at 500mv at startup and by the time the trans temp is 88 degrees celsius the B sensor is reading 840mv and 2bar when it is expecting 0bar and less than 800mv.
Then it goes into limp mode and I lose all odd gears. I use my accessport to clear the code and once the trans cools down a bit it drives fine again.
Other than that the car drives great, I have been easy on it with about 5 launches since i bought it and zero since my oem sensor failed.
I have had two sets of dodsons installed, both appear to be faulty like the bad batch that other owners had as well.
 

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I've got a couple thousand miles on my non scaled ebay sensors. They lasted all summer when it was 100 degrees and humid out. Now it's 20 degrees at night and 40 during the day. My GF has had the GTR for the past month because she had to loan her oldest daughter her Passat for a bit. Now it's sitting outside during the night and cold soaking to 20 deg F. then going up to normal operating temps. $30 ebay sensors working like champs.
 
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