Hi everyone

 

i have a problem with my gear box recently

 

while driving the gears are dont want to change and when decide to change will change in about 4k and as well noticed today the power light is on while driving on A/T so i presume is swiching itself on power mode ?

i did done gear box check and is no code showing

 

any one can help

thank you

kamil

I would do a service on the transmission by replacing the fluid and strainer which is what has helped improved my autos shifting abilities.

Have you checked the settings for the throttle position sensor?

The unit feeds the Auto transmission ECU with information on the throttles position. If this has gone bad then the Transmission ECU won't get the correct signal to change gear at the correct rev range.

https://z32.wikispaces.com/Throttle+Position+Sensor

 

It might be worth checking the connections aren't corroded on the throttle sensor connectors and Transmission loom connectors as well.....

 

Also.... To check Transmission Fluid....

 

Warm up the engine and driving her for about 30 minutes, this will warm up the transmission. Then with the engine running and in park, dip the dipstick and check the level and colour of the fluid. If it is dark and smells burnt it could be a failing transmission.

If it is red and clean, then the fluid should be okay... Check dipstick level carefully as there is a hot and cold level on there....

 

If it isn't any of these..... and you feel able to undertake this....

 

The next step is getting her in the air, dropping the fluid if you have a drain plug, dropping the transmission sump, cleaning the wire mesh filter in the transmission or replacing it and cleaning off the metallic gunk from the magnet that sits stuck to the inside of the sump.

If you do this and remove the filter, there is an O'ring in the Transmission to filter hole. Make sure you don't damage this as it won't pick up transmission fluid if you pinch it. Like trying to suck through a straw with a hole in it!

http://www.zhome.com/ZCMnL/PICS/autoTrannyOilChange/autoTrannyOilChange.html

 

I have now spent so much time trying to sort the transmission on mine over the past few years, some of the information has now been etched onto my brain....lol

Mine all had failed solenoids in them..... and no codes were showing on test.... Finally swapped for a good working one 2 weeks ago.....

 

I hope this is helpful....

 

Russ

Edited April 16, 20178 yr by veilside01702

i have good working gearbox, just sump is bent so you can just swapped from your one. you can have it for 100 quid with ecu for it. located in Manchester

the gears are do not want to change and when decide to change will change at about 4k noticed today the power light is on while driving on A/T so i presume is switching itself on power mode ?

 

When ever dealing with auto box changing issues you have to realise there is a whole series of conditions that have to be correct for the gearbox and its controls to deal with changing gear at the correct road and engine speed, but first identifing it as an electronic fault or a mechanical fault is key.

 

The gearbox on a zed can fail internally and when it does it needs a rebuild when they do the gear change is as you describe and how the fault will present itself, that said electronic issues will also give the same issues but are more easily fixed so quite a difference between the two repairs.

 

If the gearbox fluid is clean and the correct level then without specialist line pressure equipment you cannot really test any more, changing the fluid and filter can improve a working gearbox that just needs a service, however a gearbox with blocked filter will have no drive, so its unlikely that will solve anything at this time.

 

So on to the electronics, the tps circuit as mentioned above is one of the most important settings for the gearbox to know when to change gear, it also takes speed and load readings as well as gearbox internal speed signals as part of the process but if the tps circuit is faulty or incorrectly set the change will always be compromised.

 

If the tps requires checking as well as the actual tps circuit which can suffer from water issues from leaking targa drains, check out the links below for more information about this, also it can be worth disconnecting the battery for an hour to reset the autobox ecu.

 

Speed signal is also very important, if there is any issue with the speedo or the speed signal the gear change will be as you describe, a general check of the engine set up can also have a factor as engine load is also taken into account by the ecu for the gearbox, and finally rare but a possibility is the gearbox ecu itself can be malfunctioning, however this is not often the case.

 

http://www.300zx.co.uk/forums/showthread.php?175920-Pesky-targa-drains-and-electrical-issues&highlight=targa

 

 

http://www.300zx.co.uk/forums/showthread.php?132099-Water-leaks-electrical-issues-and-targas&highlight=targa

 

 

Jeff

If it's an NA box then I have pan gaskets available if you're thinking of a fluid change. Feel free to PM me if you're interested.

 

 

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