Auto gearbox symptoms

[joejtss]

Sounds the same I think.... I've just ordered a secondhand ecu from eBay it's for a 3.0d but it was only cheap so hopefully this will eliminate or confirm ecu ;-)

[NissanGQ4.2]

ECU or TCU?

ECU = Engine Control Unit
TCU = Transmission Control Unit.

I assume they are still 2 separate units like the GQ's, not even sure if a 3ltr ECU would even work properly in a 4.2

Gearbox problems can be numerous things, Faulty TPS, Worn out friction plates, the list is endless unfortunately and is a matter of eliminating them one by one.

I have not really looked at the GU manual on here but it may have a list of things to check and in what order like it does for the GQ's

If you have a reliable Transmission mob over there I would pay them a visit.

[joejtss]

Sorry poor terminology tcu yes......there are 2 unit I've just called the tcu the gearbox electronic control unit (ecu) ... My mistake... My thinking it was going to work properly as I'm sure the mapping will be different for different engine characteristics.....? There lots of auto transmission repairers just none close by... So it will have to be transported abot 200k's... So my thinking of changing the tcu If the tcu is u/s then hopefully a swap will at least help me hopefully eliminate or not as the case maybe.... I know it's a long shot but gotta be worth a try ?

[NissanGQ4.2]

It is a long shot but exactly the same thing I did when I had problems with my GQ auto, I was lucky enough 2 have the opportunity to borrow my uncle's Patrol and swap them over. Unfortunately it didn't solve the problem and a full rebuild of the gearbox followed. Found a few worn friction plates, broken wire on one of the temp senders.

[joejtss]

That's the thing .... I've checked all the inputs to the tcu position sw, voltage, revolution sensor temp sw temp sender auto !
/power/hold switch and as far as I can tell there all there inc good earths ....there's no outputs to he box although I can simulate and actuate the shift solenoid a .... Took the pan off the box no debris in there had the filter of and clean. As a whistle fluid was a good colour .... Unless I'm missing the obvious which is highly probable ... :-) I followed your rebuild thread very impressed there mate good work fancy a plane trip to 'old South Wales' if the ecu doesn't fix mine?? Lol I won't mention Johnny wilkinson and you could tell me how much of a docking were getting in the cricket !!! ;-)

[altech]

Hi Joe, mine was playing up like yours, found that the timing was out a lot . don't know if yours is petrol regards Alex

[NissanGQ4.2]

3. POWER light isn't on but came on once recently it doesn't show if i select AUTO/POWER, it's permanently off however the hold light shows

I'm unfamiliar with the GU setups, but mine in the GQ is a 3 way switch...... Up - Power, Middle - Auto, Down - Hold

Selecting Power a light comes on ( think orange )
Selecting Auto there is no light
Selecting Hold a light comes on ( think Green )

So what does yours do when you change from power 2 auto 2 hold back 2 auto???

[NissanGQ4.2]

Hi Joe, mine was playing up like yours, found that the timing was out a lot . don't know if yours is petrol regards Alex

Alex, so I assume fixing your timing fixed your gearbox issues then?

[joejtss]

Mine doesn't do anything it won't light the power light at all ... I've checked it works tho Alex mine is a diesel 4.2t

[NissanGQ4.2]

Mine doesn't do anything it won't light the power light at all ... I've checked it works tho Alex mine is a diesel 4.2t

How did you test it, have you taken the switch out to make sure its connected properly. So it doesn't light in the Hold position either?

If this isn't working how it should than it could be the reason for your issues

I'm no mechanic far from it but sounds like its in the stuck in the Hold position and holding second gear when in Drive