Nissan Repair: Pathfinder Transmission Codes, nissan transmission, nissan dealership

Question
Regarding
94 Nissan Pathfinder
Auto Trans

Hi Von,
I've been following some of your comments on Nissan transmission self diagnostics. And you may be one of the few people that knows about single digit codes.

This is what my Pathfinder is doing. [from a person on a Nissan forum ]
I have a Pathfinder that likes to shift down from overdrive and sometimes into 3rd gear when I am driving 65 -70 mph on the freeway. The engine RPM goes from 2500 to 4000 instantly. This is an intermittent problem that seems to be getting worse. Strange thing is when I let off the gas when this occurs, the engine RPM goes to idle!

I'm assuming this is a fail Safe Mode ?

I ran the self diagnostic. I got a code 5.
[ A solenoid problem? ] A Nissan dealership diagnostics pointed to this also.
Pre timing belt, rough engine... no one would commit to the scan.

Engine is now fixed. Timing belt, oxygen sensor etc.

Still was having the same trans problem described above.

I take it to Cottman Transmission several days ago. They get a 10 and 45 code. We proceed to drop the pan and  they find brass shavings.

I opt to put the pan back on  and slow the decision making down on committing to more money on this vehicle.

I drive the car home, 30 miles or so at 50 mph.
No trans symptoms.

Out of curiosity I run the self test again. No codes show.

I'm not thinking,  that my trans has a clean bill of health. I am hoping the trans fairy comes tonight and gives be a couple of bucks for it.

So what is code 5.
Any other thoughts would be greatly appreciated.

Thanks,

Scott

Answer
Scott,

The transmission is probably on the way out since you had shavings in the pan.  But, I would say to run it to failure if it is continuing to work fine.  There are a couple of things that do strange things on late model transmissions.  The first is the filter is polyester and these get gummed up so a filter change does wonders.  The second is the transmission throttle position linkage.  This tells the transmission where to shift and if it is adjusted too tight it will cause the downshift you describe.  If it were me I would drive it until it dies.  The second thing is that if it is downshifting now I would loosen up the transmission cable linkage from the throttle just a half a turn or so to get it to stop downshifting at driving speed.  Email me back with questions and such.