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Urgent: Codes P0746 and P0797

8.8K views 25 replies 9 participants last post by  SJL  
#1 · (Edited by Moderator)
Initially took the car in for a P0840 code which was deemed pressure sensor, car drove after i turn it off and on, drove for few days after. All sensors were later changed to Dodson Sensor (including line sensor). After installation car ran fine for few miles then bam!! received a P0746 & P0797 code. Entire trans was dropped again and they found small leak on clutch basket, repaired the seal with viton seal to include both input and output shaft seals. After the shop put everything back together and they clear the codes, the codes keep coming back up after driving for like few miles along. Not sure if the heat has been attributing factor or what but never had these codes until after the pressure sensors were replaced. Trans pressure seems good, VB was even sent out cleaned and tested and everything seemed to be in good working condition.

Work Done.

All Dodson Pressure Sensors
Clutch Basket Viton Seals
Input/Output Shaft Seals
Shims
Dodson Oil

Symptoms:
Car Stays in automatic mode
Power Steering Stiffs Up
Gears 1,3,5,R

2vts1mq.jpg


2010 GTR
Bone Stock

Please any feedback would be preciate so i know what possible parts to get. Just getting frustrating think of thinking bout dropping the tranny all over again
 
#2 ·
Dropping the tranny? From what I read, the solenoids are accessible by just dropping the pan.

Both of those codes are for solenoids A and C respectively for P0746 and P0797. You haven't left square 1.

More info needed, maybe someone on the board can help steer you towards an expert shop.
 
#3 ·
Hey Thanks Jaguar, The shop was saying possible the clutch basket or seal could cause those codes.... but i have no idea. You know of any shops in SoCal that is expert and done multiple GTR Transmissions in California?
 
#4 ·
I think the most knowledgable shop in SoCal has to be SP Engineering http://www.sp-power.com

It looks like their website is undergoing maintenance or changes, don't let that dissuade you.

When the R35 hit our shores, they moved away from the Supra MA80 platform to specialize in GT-Rs and awesome builders having seen their work up close.

It's not just a shop, they are GT-R cult. Always good to get a phone consultation and second opinion!
 
#5 ·
If it's a clutch basket it's either working or it's not....no in between. There would not be a code for a mechanical failure of the basket....except maybe the clutch overheat when the basket first lets go. That's what happened when the basket failed in my 2009.
 
#6 ·
The only guess they were thinking possible basket seal gone bad but at this point no clue, after just dropping the tranny not even few weeks ago and have to go do it again is a nightmare. During initial start up everything runs fine for few seconds until the transmission check is complete then after that engine malfunction then everything goes to hell.

No power steering.
In Park, car won't even allow you to rev engine.
No even gears
No Manual Mode
During start up car takes a long about close to a minute to do the Transmission check before locking down and going into limp mode
 
#7 ·
Bet you they got the orientation of the pistons are wrong when they reinstalled the valve body. The magnets all need to align with the sensors.
 
#8 ·
Doing that sets a very different set of codes. This set of codes pertains to a likely torn piston seal
 
#15 ·
I will give you one advice.. This is your second time... And if your budget allows upgrade whatever you can... If you can't work with gears... Upgrade seals and gear locks.. You don't want to face another issue in future...

Now you will be replacing piston seals.. Which means you already going to work on clutch assembly.. Go ahead and replace those baskets too.. You won't regret it...

Good luck

Sent from my SM-G900F using GT-R Life mobile app
 
#16 ·
Thanks MZAAITER would do that but already blew a lot of money from initial drop and to go all out again is almost too much. Went with replacing all seals in basket A & B and also Shaft Seals. I'll post updates after installation.
 
#17 ·
Clueless At This Moment.......
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Did a complete rebuilt of my clutch basket, SSP piston seals for both A & B and also SSP Shaft seal. Also replaced all pressure sensor A & B and also line pressure sensor all dodson. Got the car back for less than 1 hour or so as soon as i left the shop both Codes came back P0746 and 797.

Same symptoms as from before
Only have odd gears
takes couple minutes before goes in Limp mode

What else could possible be the issue at this point, i'm over $7k at this point back and forth with this transmission
 
#18 ·
The pros have spoken and also conducted repairs. Borrow a valve body from someone and swap it out (give jack a call) Its not an expensive test and worth it in my opinion.
 
#23 ·
Shit dude that sucks man. You tried a whole different valve body? It sounds like you said "got it back" as if you sent it off somewhere. I would really try a completely different one if you can.
 
#26 ·
did the clutch assembly bench test ok after the seals were replaced? From what ive heard, the Dodson pressure sensors tend to change their resistive range as trans temps increase. This is where datalogging the trans is important.