Auto gearbox problem

[foggyshaun]

Hi guys I have a 17 plate techna with auto transmission. (Not had it long) anyway when I pull up to stop and then pull away sometimes the gears don’t engage straight away, then it engages and surges forward, this doesn’t happen every time. Is this normal?
I’ve spoke to the garage where I purchased and he said it may be a software issue. Said they will take it to be diagnosed but it sounds mechanical to me.
Any thoughts?
Thanks

 

[Old.Tony]

There's a number of possible reasons for this, from low oil level to damaged turbine vanes (in the gearbox's torque converter). It might be a sticky valve that sometimes cooperates and sometimes doesn't.

If software is causing a problem like this it's usually the result of a poor signal from a sensor causing the computer to think something else is happening (either failing sensor or dirty in the connectors or wiring loom damage). The computers in these don't arbitrarily change their minds about how to change gears or engage drive - the software in them is pretty solid.

It might pay to take it to someone that can throw a scan tool on and ask the gearbox what it thinks is happening, which might point to the cause.

 

[foggyshaun]

There's a number of possible reasons for this, from low oil level to damaged turbine vanes (in the gearbox's torque converter). It might be a sticky valve that sometimes cooperates and sometimes doesn't.

If software is causing a problem like this it's usually the result of a poor signal from a sensor causing the computer to think something else is happening (either failing sensor or dirty in the connectors or wiring loom damage). The computers in these don't arbitrarily change their minds about how to change gears or engage drive - the software in them is pretty solid.

It might pay to take it to someone that can throw a scan tool on and ask the gearbox what it thinks is happening, which might point to the cause.

Hi I’ll keep this in mind when I talk to the garage, it’s going into Nissan on Wednesday so hopefully they will plug it into the diagnostics.
Thanks for taking the time to reply I will keep updating.

 

[foggyshaun]

Hi I’ll keep this in mind when I talk to the garage, it’s going into Nissan on Wednesday so hopefully they will plug it into the diagnostics.
Thanks for taking the time to reply I will keep updating.

Hi all
After a period of time when the truck was with Nissan, they completed a software update which didn’t do much to improve the problem. Then the transmission oil was changed, this improved dramatically but didn’t resolve completely. Nissan then said the gearbox will need to be changed but wouldn’t do it under warranty as it was 2 months over the 5 year warranty (not impressed).
The garage where I purchased it then flushed the gearbox through thoroughly and introduced a flushing additive (not sure what it was) then refilled with new oil.
It now drives perfectly and hopefully will continue to do so.
Apparently the gearbox oil needs to be changed every 2nd service and maybe this wasn’t done when serviced previously who knows.
Hope this helps anybody else with the same issue.

 

[Old.Tony]

So in other words, some of the valves were gunked up and the flush additive freed it enough to shake it loose.

Did they show you the oil that came out?