Nissan patrol td42 automatic transmission overdrive problem

[OLEGSUNA]

Hi ,I am russian man from United Kingdom,. This is story about my Patrol,trans-RE4R03A. I owned it for 3 years, one day transmission stopped-gone to LIMP mode. I spended 2300 UK pounds for recon.1 Year garantee or 12000miles. Box worked absolutely fine. After 15 months of recon. one day on motorway box lost overdrive(4TH GEAR) and car was like stupid, box did not knows what need to do.Boys from garage said garantee is out of date-sorry,but they also said it looks like electrics problem.
What happened next- I exchanged ATF, recon.alternator,fitted additional cooler for ATF,checked ATF pressure-1litre per 1 minute, today car drive perfect only 1st,2,3. The POWER button when I press it is appear on dash but no reaction on box, kickdown works fine.On speed 50miles looks like 4th want to lock up,but taho around 2200 per/m not drop on 1200 like should be. TPS looks works fine when I ajust it loads of reactions to box.
Russian forums said 50% ATF themperature sensor is the reason,this sensor allows POWER button to overdrive,or revolution sensor.I dont know location of themperature sensor on box.
This problem exsist 1 year, I using car everyday, ATF colour is fine,level is ok,car has exelent power, but I not go to motorway.
Finnaly, Australian people who knows about Patrols 100%, please any advise to find reason.Olegs

[Bigrig]

G'day Olegs! Welcome aboard mate - one of the mods may move your thread to the introduction section as we ask people to introduce themselves before asking questions, but no harm done mate, as you may not have seen that.

It's the start of the workday here mate so someone will be along to answer your question no doubt!!

[Sir Roofy]

welcome aboard olegs
sure to be someone to help you out

[boggy2006]

hi, the auto does wait for a certain temperature to be reached before going into lockup, but on my TB42e it will go into overdrive (4th gear) from cold, but doesn't lock up the converter until warm. When you accelerate through the gears, is it only changing from 1-2-3 and not 4th?

With the transmission control unit disconnected completely, my GQ will set off in 3rd, but still changed to 4th. Might be worth trying this to see if it's still mechanically able to use 4th.

To check the electrics (if you have a volt meter, locate the TCU (passenger side left kick panel), looking at the front of the TCU, connector end, check pin 9 of the left 20 pin connector (pin 9 counting across the top row of the connector, looking into the connector face of the unit), this should be 3-8v when power shift is in auto.

Check pin 12 (2 pins in, bottom row), should be 1.56v when cold and 0.45v when hot. This is the temp sensor.

On the right connector (16pin connector), check pins 35&36, bottom right 2 pins looking into the connector panel, these control the auto shifts in a binary pattern. ie. one of the pins changes state for each of the 4 gears. Can't remember the pattern, but something like 0v & 0v, 0v & 12v, 12v&12v, 12v&0v. Either way, check that one of these pins change for each gear change. If nothing changes when you expect it to go into 4th, then it's an electrical problem.

[OLEGSUNA]

Thanks boys, will try to do what boggy2006 said, later will report what happened after that,olegs

[Barney56]

boggy2006 I recently purchased 2004 3L TD auto and recently noted the auto does not seem to lock up until warm/hot (about 6-10km of driving). From your note above it looks like this is normal?
Thanks
Barney

[Arman]

Its not about a Patrol but I have a Nissan March 2005,I got the same problem like you.Just go to machaniq and I think you should use good quality ATF for best longivity service.

[ablast]

I have a 1977 Y60 ST Patrol Wagon. I have the same problem with overdrive not engaging in my auto. If and when you find a solution the problem I would be most interested to know the outcome and what the problem is. Mine has perfect gear changes, very clean fluid, no filings or bits on the magnetic plug and no aparent reason why it won't change into overdrive when the button is pushed in. I have been doing a few miles and I am sure the extra fuel is costing me dearly.

[Peacemaker]

There is a temp sensor in the pan area screwed to the valve body this seems to be 90% of issues with autos not going in to OD you can drop the pan and replace the temp sensor or you can use a couple of resistors to trick the auto computer to think its warm. There was an article on one of the forms but i cant find it

[NissanGQ4.2]

Info on the RE4R03A Auto can be found here :http://www.nissanpatrol.com.au/forum...earbox+rebuild

Location of the Temp Sensor and Switch in my RE4R03A Gearbox

TempSensorandTempSwitch.jpg

Cheers

Todd