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100 SERIES A750F TRANSMISSION 4TH TO 5TH NO UPSHIFT & NO LOCK OUT

Donna Ware

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Joined
Dec 15, 2017
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4
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australia
Hi all
We bought a 2006 Sahara in July 17. Picked up Aug from Toyota. Sep, replaced Chipit Chip with a DTE chip. Have driven about 1000k before transmission stuffed itself. Oct had transmission rebuilt. No upshift from 4-5.

Went to Toyota to diagnose. No fault found. Went back to transmission rebuilder...no fault found. Went to Chip installer...no fault found.

Do it ourselves...found a few faults....Turbo boost sensor stuffed. Throttle motor controller - pins corroded (now cleaned). L4 position switch replaced. Still no 5th.
Using ATF WS oil in transmission.
We have borrowed a Snap on diagnostic kit and checked all pinouts. Found a couple more issues but we are yet to find out why upshift to 5th not working. It has intermittently worked a couple of times where it has shifted to 5th and locked in but with no explanation as to why.

Does anyone have any ideas as to what could be wrong?

If we find something in the mean time, I will give you an update.
 
UPDATE

We now have 5th gear. We will see how it goes for the week before scream hallelujah. We took the DTE chip out and the turbo smart booster valve off the waste gate pressure control line. It worked straight away. We had that chip fitted and then about 150kms later we blew a tranny. So we will see if this is it.
 
Hi Donna we have a 2003 sahara 5spd auto that is failing to lock into 5th all others gears are fine.
Vehicle recently lost all drive and mechanic said "rod had popped out" in pan never had 5th since and mechanic is stumped.
Have you any ideas?
Regards John
 
Hi Donna we have a 2003 sahara 5spd auto that is failing to lock into 5th all others gears are fine.
Vehicle recently lost all drive and mechanic said "rod had popped out" in pan never had 5th since and mechanic is stumped.
Have you any ideas?
Regards John
Gidday John
Not sure what engine is in your vehicle but mine is 1HDTFE.
In the end it was the connector on the throttle motor controller which a bad connection this showed as a code on the engine side code p1222. Even after completing a full ecu pin out on engine and trans i was stumped, as it passed. I can only assume that every time i moved the conector it pinned out OK.I replaced the connector and no further issues, about $25 on ebay for a 1JZ,2JZ & 1UZ. My suggestion is find someone with a scan tool and check the codes current and stored. If there is no codes then drive the vehicle and read the live data watching for the trans to request 5th gear electronically, if it requests it electronically and still no 5th gear then it could be and internal issue. Although from all my findings there is only 1 other thing that could lock out 5th gear and that is the low range switch on the transfer case. i can't remember if the transfer switch is normally open or normally closed but a simple check is unplug it and drive if no change then bridge the plug and try again. This will show no code.
Not sure what state your in but I am in Perth W.A. if you are anywhere near Bayswater Victoria I highly recommend Wholesale Automatics. Even if it's for a brain pic they are a great company with insane knowledge.

Hopes this helps you and good luck.
 
Gidday John
Not sure what engine is in your vehicle but mine is 1HDTFE.
In the end it was the connector on the throttle motor controller which a bad connection this showed as a code on the engine side code p1222. Even after completing a full ecu pin out on engine and trans i was stumped, as it passed. I can only assume that every time i moved the conector it pinned out OK.I replaced the connector and no further issues, about $25 on ebay for a 1JZ,2JZ & 1UZ. My suggestion is find someone with a scan tool and check the codes current and stored. If there is no codes then drive the vehicle and read the live data watching for the trans to request 5th gear electronically, if it requests it electronically and still no 5th gear then it could be and internal issue. Although from all my findings there is only 1 other thing that could lock out 5th gear and that is the low range switch on the transfer case. i can't remember if the transfer switch is normally open or normally closed but a simple check is unplug it and drive if no change then bridge the plug and try again. This will show no code.
Not sure what state your in but I am in Perth W.A. if you are anywhere near Bayswater Victoria I highly recommend Wholesale Automatics. Even if it's for a brain pic they are a great company with insane knowledge.

Hopes this helps you and good luck.

Thanks Donna i went for a drive this morning and everything was fine it went in and out of 5th flawlessly so will wait and see what develops.

Regards John Jennings
 
Hey guys im after some info regarding the cruiser that had the chip removed, was it found that the chip was causing the issue? And when the transmission had failed was it 4th & 5th that went? Reason im asking is i have a customer who is seeing the same issue by the sounds. Any incite would be ideal.
 
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Hi Craig, I'm also looking into this. My 2004 HDJ100R has developed the same issue. It won't upshift from 3rd. No fault codes. I'll scan for codes first. Anyone else come across this problem?
 
I’ve copied my reply to a similar post in 2020 which might just help someone out! I should still have the part no for the loom if you need it

“I had a similar problem on my 2004 5 speed 100 a few years ago, it suddenly stopped locking up, there were no warning signs and I didn’t have the intermittent fault you’ve had. I eventually found that there are two temp sensors in the auto box, one feeds the transmission temp warning light, the other prevents lock up until the fluid reaches a preset temp as Uhu has said and that had failed.
If you do have the 5speed, the sensors are an integral part of the loom inside the box, the other connections are for the solenoids.
Once you drop the pan it’s an easy job to change, it feeds in from where the multi plug fits on the side of the box and you’ll also be able to clean the filter while you’re at it.
The filler plug is tucked away on the opposite side of the box to the multi plug, it is NOT a level plug, however there’s plenty of info on how to fill to the correct level, the plug will probably have WS stamped on it in which case you will need the correct Toyota WS atf.
If you’re going to do this yourself, be careful when you release the pan as there is still plenty of atf in there once you have emptied it via the drain plug!”
 
Hey guys did anyone have any luck with the no 4th/5th lockup issue and what was causing the trans to fail? rebuilt trans and it wend fine for a few weeks then lost lockup and 4th again? expensive exercise without really getting to the bottom of the issue. There is obviously something causing the trans to slip and fail in the higher gears?
 
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