ER34 RB25DE Auto - Would a flush ever fix an "A/T" light?

[thatjawncrazy]

gentlemen (and others)...

at 157k km on my rB25DE auto sedan and am getting an every-so-often A/T light, with the usual loss of whatever gear i'm in at the time. it always goes away once i restart, but i read the threads and watched every video and am told it will only get worse.

i have zero evidence anyone has ever done a trans flush on this car.

is there a chance that doing a flush will fix the problem, rather than the usual "replace the A/B solenoids"? just curious. rather not flush, seal it up again, then have to drop the pan all over again...

 

[GTSBoy]

Get a scan tool on the Consult port and see what the TCU has to say for itself.

[thatjawncrazy]

5 minutes ago, GTSBoy said:

Get a scan tool on the Consult port and see what the TCU has to say for itself.

was my first thought, but a couple hundred for the cable/adapter plus not having a laptop that can run NIstune/NDSI/ECUtalk or any of the usual programs is the issue.

honestly i'm going to flush it anyways and so i guess this is a little like asking people to internet-diagnose my car. 

just wanted to see if anyone's ever had an A/T light go away purely by doing this though

[GTSBoy]

Just go to a quality workshop that has a quality scan tool and ask to plug it in for a few minutes. Throw them a six pack.

[thatjawncrazy]

On 10/28/2024 at 6:37 PM, GTSBoy said:

Just go to a quality workshop that has a quality scan tool and ask to plug it in for a few minutes. Throw them a six pack.

Nobody around me has a Consult (USA east coast)  

Either way I ordered all the parts to do a trans flush so guess I'll do it anyways.

[GTSBoy]

4 hours ago, thatjawncrazy said:

Nobody around me has a Consult (USA east coast)

It's just not true. It does not have to be a "Consult". Professional grade scan tools from EVERY major workshop equipment electronics manufacturer will happily interrogate Nissan electronics. Things like Snap-On scan tools, etc. That is what they are for. This is why I said...

On 10/29/2024 at 9:07 AM, GTSBoy said:

Just go to a quality workshop that has a quality scan tool

 

[thatjawncrazy]

On 11/1/2024 at 5:38 PM, GTSBoy said:

It's just not true. It does not have to be a "Consult". Professional grade scan tools from EVERY major workshop equipment electronics manufacturer will happily interrogate Nissan electronics. Things like Snap-On scan tools, etc. That is what they are for. This is why I said...

 

if I find a shop that has an OBD I tool and can connect it to the port - i wonder what the suggested route is for purposely triggering transmission limp mode while i happen to be within driving distance of the shop, and then dropping everything to stop by and have them scan it. so, it would be nice if things worked out that way - but in case they don't, we are back to my original question of "will bad fluid ever trigger limp mode on its own".

[GTSBoy]

If it has had a code in the recent past, the code should still be there waiting to be read.

[thatjawncrazy]

interestingly enough, i found out the answer is yes. doing a flush did fix my recurring A/T light. it might have been because of the trans filter:

but that doesn't really make sense to me. the fluid/filter was super dirty. would that increase the pressure in the lines and trigger an A/T light? does the car even have a way of detecting that? i have no idea. i've done 200+ miles after the flush and no A/T light. if my A/B solenoids went bad, i would think the light would've come on.

shifts and drives way better now though...at 2k rpm instead of 2500...no hesitation and downshifts when i want it to. 

[GTSBoy]

Well, if that filter was impeding fluid flow, then it could have similar effects to faulty solenoids. The TCU will register a fault when it does something (ie, changes the state of a solenoid) and does not detect the required result. If there are other causes that can make the same lack of result, then they will be indistinguishable to the expected cause for which the TCU has a code.