TT Auto not shifting in 4, no manu light

Hello guys. I am having some trouble with my auto transmission on my 94 TT JDM bpu supra, it won't shift to 4th gear and manu button doesn't light up. Overdrive is working, the oil level seems fine, car is in good condition, and i get error 89. My car was stored for the winter, about 3 months and when I took it for a ride this spring I got this issue. Any ideeas?

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And by the way, I didn't do any donuts, or burnouts, I was very gentle witht it and i use to play with the manu mode last summer

That's a "6 Million Dollar Question"!

Many before you have asked this same question, however, either many of these have learned to live with it, or have been waaay too ignorant to post up the fix?

This link https://www.google.co.uk/search?q=Toyota+Supra+fault+code+89&rlz=1C1CHBF_en-GBGB703GB703&oq=Toyota+Supra+fault+code+89&aqs=chrome..69i57.5026j0j7&sourceid=chrome&ie=UTF-8

Will take you to links for several different possible error 89 fixes including;

Odo swap

Delimiter/speed-converter &/or it's wiring

Loom fault

TPS setting

Traction-Control stepper-motor operation

A speed-sensor

Auto to manual conversion result

Traction Control ECU

Engine or/& Transmission ECU.

Please post up which one worked for you?

Thank you.

Thank you, I already search that code but I don't think that's the reason 4 gear won't work.

If overdrive is working that is your 4th gear. As positions 1 and 2 should be obvious, D is 3rd and 4th is OD with the button pressed in.

But still 4 gear does not come in, i hit the redline at 200km/h and 4 gear won't come

Does it bounce off the limiter in 3rd? Or does it feel like you’re hitting the brakes at 200km/h? If so then its you’re speed limiter. If you are cruising at 100km/h and turn overdrive off does it drop down to 3rd?

It bounces off the limiter, the car is delimited. And the overdrive I don't know, I will check

I've just had this on the way home!

Fluid is fresh and ok level wise, I think it's electrical given there are no other issues in shifting and never have been.

The manual says you can perform a test where you disconnect a solenoid (I think it's No.1 and 2 speed ones near the rear of the box where the prop joins it - manual is not very clear) and then it'll only shift using the stick. But this means it will start in 2nd in 'L' and then a shift to '2' gives third and 'D' gives fourth/OD. So I plan to do this to 100% it as electrical not mechanical......then I'll head back to the manual at some point.

Over the weekend I flushed my heater matrix and am wondering if the hose down the back of the engine may have drenched something, although it's been fine since for 50 miles and a few trips so could be coincidence.

http://www.mkivsupra.net/vbb/showthread.php?283708-No-reverse-gear-Autobox-need-help/page4&highlight=autobox+solenoids

Just been searching here and found this which may help......

I have a spare ECU about so may just try that in case, mine is an 94 and so may be suffering some ecu degradation?

http://www.mkivsupra.net/vbb/showthread.php?283708-No-reverse-gear-Autobox-need-help/page4&highlight=autobox+solenoids

 

Just been searching here and found this which may help......

 

I have a spare ECU about so may just try that in case, mine is an 94 and so may be suffering some ecu degradation?

Sounds like the auto ecu to me. I had some bizarre stuff happening after we had finished rebuilding my car, like I couldn’t use manu mode and flashing Od lights for no reason. Did you pull the fault codes from the auto box?

I can dig out the thread where Im sure I posted up more info but after going through the entire car and even replacing the box with a new titan race one, it was the auto ecu at fault. Leaky capacitors iirc is common for these ecus now they are 20 plus years old. There is a guide on replacing them somewhere to prevent issues on known working ecus also. But new ecu totally sorted the weird behaviour

That post could apply equally to scooter and the OP! Would be the first thing I would replace anyway, as we spent a long time to get to that point..!

Well it's the easiest thing for me to try, as I have a spare one and it's passenger footwell fiddling only! I know it's the sort of last thing in the manual flow charts, ie it's says do this measure that if all that is a no 'then replace ecu' tends to be the final thing, but seems there is enough evidence to point to the ECU at least being a contender.

For the record a long while ago I got the flashing slip and o/d symptoms, I decided on removing the dials and 'strategically' removing a bulb or two, so the diagnostics thing is not currently an option.

So swap ecu, see what happens, if no dice, dials out, bulbs replaced and go from there re diagnostics etc.

Well it's the easiest thing for me to try, as I have a spare one and it's passenger footwell fiddling only! I know it's the sort of last thing in the manual flow charts, ie it's says do this measure that if all that is a no 'then replace ecu' tends to be the final thing, but seems there is enough evidence to point to the ECU at least being a contender.

 

For the record a long while ago I got the flashing slip and o/d symptoms, I decided on removing the dials and 'strategically' removing a bulb or two, so the diagnostics thing is not currently an option.

 

So swap ecu, see what happens, if no dice, dials out, bulbs replaced and go from there re diagnostics etc.

The flow charts don't account for the 20 plus year old age of the parts now though! The ECU should be moved near the top of the list IMO, even one of the ones I bought as a replacement was faulty, but with different behavior. Let us know how it goes, hopefully that will solve it but if not, fault codes like you say.

As it happens, I currently have the exact same problem. Doing a diagnostic test on the trans side, brings up error code 89, which is linked to the trac system. I've sourced another trac ecu to try, but I don't think it will fix it.

I don't have a spare ecu to try, so if it fixes your problem, I'd be keen to know, as it might be the same with mine

Pretty sure I had fault code 89 Gaz... May be worth opening your ECU and seeing if you can visually spot anything up with the capacitors. However mine looked ok but were not..!

Pretty sure I had fault code 89 Gaz... May be worth opening your ECU and seeing if you can visually spot anything up with the capacitors. However mine looked ok but were not..!

Cheers bud. Mine is a total dick to get to, due to the wiring loom and fcon that's hooked up in the footwell!

Hopefully the op will have a chance to try his, before I get the opportunity to check mine, and at least I'll know if it's worth delving in!

I am a newbie, so I am curious if you guys figure this out. I think it's a sign that our supras want to me swapped to manual gearbox....

I had this issue and it as caused by 2 blown capacitors in the ecu.

Guys will be swapping in a spare ecu tonight and will let you know how it goes, it sounds promising from the reports coming in, it would be nice if my parts hoarding pays off for once!

If it sorts it then I'll open up the old one and see if anything looks untoward and then I will try and get it repaired....

Cheers bud. Mine is a total dick to get to, due to the wiring loom and fcon that's hooked up in the footwell!

Hopefully the op will have a chance to try his, before I get the opportunity to check mine, and at least I'll know if it's worth delving in!

 

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It's worth it for sure. It's the most likely cause IMO, certainly the first thing to rule out. When Toyota wrote their fault finding manual the car wasnt 25 years old!! These ECUs are failing left, right and centre on Toyota and Lexus of that vintage.

Well I didn't want to be too confident it would be the easiest (for me) solution but it appears to be! ECU swapped in off up the road and over drive button doing what it should and 4th gear available, so thanks for the comments/nudges to try that first, at least all your previous efforts saved me doing the same and gave me a fast track.

Will open up the ecu over the weekend to see if I can see evidence of damage. If anyone has repaired one let me know where they had it done, cheers all.

I had the exact same problem spoke to Davidp who told me to swap the ecu ,couldn’t find a swap so took the ecu out and when I looked inside one of the capicitor had burst leaked on to the board ,got it repaired at my local tv repair guy and it’s been great ever since ,and it only cost me a tenner.

Well I didn't want to be too confident it would be the easiest (for me) solution but it appears to be! ECU swapped in off up the road and over drive button doing what it should and 4th gear available, so thanks for the comments/nudges to try that first, at least all your previous efforts saved me doing the same and gave me a fast track.

 

Will open up the ecu over the weekend to see if I can see evidence of damage. If anyone has repaired one let me know where they had it done, cheers all.

Result

There should be a new sticky thread, 'Is your autobox misbehaving? overdrive issues? incorrect gear selection?' replace the ECU first!.

I recall getting to the bottom of mine was like a month long childbirth. Nearly went manual!

Result

There should be a new sticky thread, 'Is your autobox misbehaving? overdrive issues? incorrect gear selection?' replace the ECU first!.

 

I recall getting to the bottom of mine was like a month long childbirth. Nearly went manual!

Yeah me too I was pulling my hair out

Well I didn't want to be too confident it would be the easiest (for me) solution but it appears to be! ECU swapped in off up the road and over drive button doing what it should and 4th gear available, so thanks for the comments/nudges to try that first, at least all your previous efforts saved me doing the same and gave me a fast track.

 

Will open up the ecu over the weekend to see if I can see evidence of damage. If anyone has repaired one let me know where they had it done, cheers all.

See my post 22