Hi, just Got the car back up and running after a gearbox change, previous box showed signs of internal damage ie intermittent gear selection problems, but what ever the problem it would never get out of 2nd. At the time i never checked fuses, Gearbox ECU etc.. i was told the box needed changing and took it on faith. However , now the new box is installed (which was taken on faith yet again it was fine) when i took it out for its first run, it would only use 1st and 2nd in D mode. i have recently had it pointed out that the problem might be external to the box ie the fuses, Gearbox ECU, etc...

 

So i have found out how to put it into diag mode, which i will try soon and give the results, i found this site

 

http://z32.wikispaces.com/Automatic+Transmission+Diagnostics

 

which looks great anyway in case anyone hasn't found it yet. i know where the Gearbox ECU is located but need to know if the GB has any fuses that blow and if so where are they

 

I cant think of any other issues that might affect the smooth running of the box but again, if anyone knows better please advise.

 

Another question, when i press the overdrive? button, a light illuminates on the RH set of warning lamps called "MISSION OIL" (i think it means transmission oil) has a wire gone astray? have i somehow got a rogue dash unit.

 

Kind Regards

 

Rich

Quick test, with ignition on but not running select reverse and then see if the reversing lights have come on, if not the fuse for the autobox has gone ( more common than you might think and not caused by the box itself) go to the fuse box in the drivers foot well, bottom row, 2nd from the right red 10 amp, shown on fuse cover as ASCD + A/T Control

 

If the reverse lights are working you know there are is no power feed issues, you could have issues with the tps, the autobox ecu, speedo issues, speed sensor issues, gearbox rev sensor issue or even bad luck of a second bad gearbox although I would do more checks before you conclude that yet.

 

One more thought, was the torque converter changed also?

 

Here is the autobox self diagnostic procedure with fault codes

 

http://www.zedworld.co.uk/wizzj.html#auto_box

 

Jeff TT

Quick test, with ignition on but not running select reverse and then see if the reversing lights have come on, if not the fuse for the autobox has gone ( more common than you might think and not caused by the box itself) go to the fuse box in the drivers foot well, bottom row, 2nd from the right red 10 amp, shown on fuse cover as ASCD + A/T Control

 

If the reverse lights are working you know there are is no power feed issues, you could have issues with the tps, the autobox ecu, speedo issues, speed sensor issues, gearbox rev sensor issue or even bad luck of a second bad gearbox although I would do more checks before you conclude that yet.

 

One more thought, was the torque converter changed also?

 

Here is the autobox self diagnostic procedure with fault codes

 

http://www.zedworld.co.uk/wizzj.html#auto_box

 

Jeff TT

 

Jeff, Hi Again. Thanks for the info, much appreciated, Checked the rev lights, they came on, Also checked fuse, it was okay. The Torque Conv was also changed as my car is a NA auto and I used a TT autobox, I know, I can hear you cringing from hear.... sorry but I had to do it. I had a look at your self diag link, great, however, which light is supposed to flash? and where is the A/T light supposed to be that lights up?

 

Hope all is well

 

Regards

Rich

AT light to the left of the steering cowling at the bottom of the dash, i have posted up the dash layout in your other thread

Graham, Thanks mate, if not for finding the english translation... however i'm still trying to nail down these areas, Dave Zed says he hasn't a clue, as you probably dismantle more dash units than any one else, i thought you might have a clue.

 

I dismantle dash's but have little to do with the surround lol, but from memory-ish you have Washer fluid level light, O/D, AT, CC...

 

If you shine a torch at the symbols look at an angle and you should be able to see what each symbol states, sorry cant be more specific.

Groover, on the big picture above of the dash, it shows 4 instrument lights top left above the speedo and top right above the rev counter, on my dash, i dont have these in this position.

 

 

When i dismantled my dash and shone a light, i saw these instrument lights

 

 

 

When i activate the OD switch the Mission oil light comes on and when i place the A/T hold switch in hold, the Diff oil light comes on.

 

The biggest problem i have is i dont seem to have a AT Power indication light, which means i am unable to carry out a diagnostic.. Jeff, if you have any input on the different dash's that are used, please shout.

 

And if anyone has any more suggestion as to why i'm stuck in second, please help.

 

regards

 

Rich

If im reading this right, you have an N/A right? I dont have half those light symbols on my NA dash surround, obviously wouldnt have the hicas lol, but im sure the middle top should be AT. Have you changed the dash or surround at some point?

I will have a look at my UK spec auto tomorrow to see what the symbols are and see if i can shed any light on the situation.

As far as the dash itself i think the top one is a later series dash.

 

You may have an issue with the auto ecu, or TPS out of range as far as the gears not selecting above 2 or you have some wiring in the wrong plugs, ie when you switch overdrive or hold there should be a light each on the dash surround but lighting up in the wrong place on the surround.

Ok just to clear up the misunderstanding here, there are a many varients of the zed dash warning light layout, below is a series 1 & 2 import layout for the autobox only.

 

The 3 lights POWER, OFF and HOLD refer to:

 

1) Power light = when hard acceleration ( kick down) operated for longer than 5 seconds and then gives 10 seconds of sports mode (6k revs change pattern)

 

Note: This is also the light to watch when doing the built in diagnostic.

 

2) O/D off = simply means the overdrive button is in the off position this means you have only 1, 2 and 3 rd gear, no over drive or torque lock up ( feels like 5th gear)

 

3) Hold = this is when the hold button is active and no first gear is used, this helps in ice or snow conditions pulling away in 2nd gear to help prevent wheel spin.

 

Note: Hold can also be used as an economy mode, up change is sooner into the higher gears and the gear holds longer before changing down.

 

 

It would appear from your pictures you have a UK twin turbo bezel hence why the problem with the lights, the position remains the same so a mental re-label will be fine for now.

 

Oh twin turbo auto box and non turbo auto box are not really a direct swap, different shift patterns and a different ecu for controlling it, tried it once 10 years ago and it did not work well for us, although others say it has, jury is still out on it in my view.

 

Jeff TT

Edited February 14, 201411 yr by JeffTT

Interesting and informative thread guys.

Ok just to clear up the misunderstanding here, there are a many varients of the zed dash warning light layout, below is a series 1 & 2 import layout for the autobox only.

 

The 3 lights POWER, OFF and HOLD refer to:

 

1) Power light = when hard acceleration ( kick down) operated for longer than 5 seconds and then gives 10 seconds of sports mode (6k revs change pattern)

 

Note: This is also the light to watch when doing the built in diagnostic.

 

2) O/D off = simply means the overdrive button is in the off position this means you have only 1, 2 and 3 rd gear, no over drive or torque lock up ( feels like 5th gear)

 

3) Hold = this is when the hold button is active and no first gear is used, this helps in ice or snow conditions pulling away in 2nd gear to help prevent wheel spin.

 

Note: Hold can also be used as an economy mode, up change is sooner into the higher gears and the gear holds longer before changing down.

 

[ATTACH=CONFIG]77240[/ATTACH]

 

It would appear from your pictures you have a UK twin turbo bezel hence why the problem with the lights, the position remains the same so a mental re-label will be fine for now.

 

Oh twin turbo auto box and non turbo auto box are not really a direct swap, different shift patterns and a different ecu for controlling it, tried it once 10 years ago and it did not work well for us, although others say it has, jury is still out on it in my view.

 

Jeff TT

 

seet wondered what the hell they meant lol

I recently became the owner of a JDM 1990 TT auto that has a gearbox problem...(no reverse and horrible "grunching" noises in drive) :oops:

 

I had assumed that it was shot and needed replacing/...but then came across this post.

 

I was about to follow the diagnostic routine until I read the instructions to put the lever in "2" and then into "1".....as well as the above issues is will not go into "2" as well....so should I return to my original assumption that the whole unit needs replacing!

 

If that is the case...would a UK spec TT auto box fit a JDM TT ?

 

Thanks

Yes a TT autobox is the same fitment:thumbup:

i have changed four auto gear boxes on my one...if you hear the grinding noise and it won't change up ..the box is gone...the fifth time i have converted mine to manual...more fun with no problems

Hi, been doing some searching and cannot find any help. Bought my second 300tt cheap with an auto problem. Will convert to manual at some point, but for now need it driveable. Problem is it only has first, second and reverse. Also it idles ok but when raising the revs, it kind of pulses. Ran auto diagnostics and have code 3, throttle circuit shorted or unplugged. reset the tps, no change. Changed tps for a known good one, still no change. Any help on what to try next, please?

Hi, been doing some searching and cannot find any help. Bought my second 300tt cheap with an auto problem. Will convert to manual at some point, but for now need it driveable. Problem is it only has first, second and reverse. Also it idles ok but when raising the revs, it kind of pulses. Ran auto diagnostics and have code 3, throttle circuit shorted or unplugged. reset the tps, no change. Changed tps for a known good one, still no change. Any help on what to try next, please?

How did you reset the tps ? did you read the value at closed throttle? if so what the value? should be around 0.45v, if massively high you have a short circuit on the circuit, this will definitely fault the auto box as you mention.

 

Checkout this link of mine from some time ago which explains about what goes wrong with the tps circuit and how to fix it.

 

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

 

Jeff

Edited January 29, 20169 yr by JeffTT

How did you reset the tps ? did you read the value at closed throttle? if so what the value? should be around 0.45v, if massively high you have a short circuit on the circuit, this will definitely fault the auto box as you mention.

 

Checkout this link of mine from some time ago which explains about what goes wrong with the tps circuit and how to fix it.

 

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

 

Jeff

Edited January 29, 20169 yr by JeffTT

I set it to 0.45v throttle closed, it also shows 4v throttle open. Which I think is correct?

I set it to 0.45v throttle closed, it also shows 4v throttle open. Which I think is correct?

I set it to 0.45v throttle closed, it also shows 4v throttle open. Which I think is correct?

 

Ah, that is the correct setting my friend, so forget my link that is not your issue, sadly it looks to be a failed box.

 

Jeff

I set it to 0.45v throttle closed, it also shows 4v throttle open. Which I think is correct?

 

Ah, that is the correct setting my friend, so forget my link that is not your issue, sadly it looks to be a failed box.

 

Jeff

really? i dont mean to question you jeff, but surely the problem is electrical? i saw a post somewhere on the internet saying that the feed from the tps goes through the main ecu before going to the auto control module and the signal can be lost in the harness between the two. im not to good with the wiring diagrams so cant really see how to check continuity.

really? i dont mean to question you jeff, but surely the problem is electrical? i saw a post somewhere on the internet saying that the feed from the tps goes through the main ecu before going to the auto control module and the signal can be lost in the harness between the two. im not to good with the wiring diagrams so cant really see how to check continuity.

its the bottom post in this link, (if it works)

http://www.aus300zx.com/forum/showthread.php?t=284634

its the bottom post in this link, (if it works)

http://www.aus300zx.com/forum/showthread.php?t=284634