Limp Mode, Auto tranny is locked in top gear!!!

[MoFo]

Hello Everyone,
Navara D40 2006, after finding a bent spade on the ignition switch which gave a intermittent fault forever before trcing it down, the geatrbox has decided not to work and stay in "Limp" mode. Is there a reset procedure to bring my baby back to life?

 

[Old.Tony]

You could try a manual reset. Having the radio PIN and writing down the trip meter values (if you use them) is helpful.

Pop the bonnet, remove the battery negative terminal then put your foot on the brake (uses up any residual power). Reconnect, the ECU (at least) will be reset, which may also reset the TCM in the gearbox.

The Nissan RE5 box uses a custom set of PIDs that I can't access with my Torque app but I know that professional mechanic's devices can - if I can ever figure out what code to query there's a few things I'd like to know from my gearbox! Until then, you should be able to get a mechanic to reset the TCM if the power cycle trick doesn't work.

Thing is though - what caused it? I guess reset it and see if it happens again.

 

[MoFo]

Hi Old.Tony,
Thanks for the dope. Yes what caused it indeed. My analysis is the one of the female pins from the connector to the ignition switch was sitting on top of the male pin, instead of inside it. Looks like a bit of Friday afternnon tiredness on the assembly line. Took some 12 years to manifest itself as an intermittent fault, and a further 3 years to find the ****er.

So after replacing the ignition switch for some unwanted practice, I straightened out the connector pins and magic. The engine fired up beautifully, just like a brand new Navara.

Now the auto Tranny won't shift and the O/D light stays on for some extra laughs.

So, I've naturally reset the ECU with the standard pedal dance and no joy. Was just wondering if there was some other piece of wonderment to emanate from possibly the worse investment in my entire life!!!

 

[Dustyfeet]

Restarting this thread, asking for help and bouncing ideas around the traps.

It appears I purchased this Ute from mofo 2 months ago; fully aware it still has some faults. Slowly trying to solve them on weekends.

The main fault is the transmission is still in Failsafe mode, solved a few other minor issues along the way.



From the start.

2006 Spanish D40 St-X YD25 diesel Automatic 4WD 218,000km



Turn key on & it’ll start, engine now smooth and idle fine.

Can drive in reverse fine, High & Low range 4WD all fine.

When in D, only has one gear, 4th gear engaged, no matter what you do, D, 3,2,1; always just 4th gear engaged.



Take a step back,

Key on to accessory, ok.

Key to ignition, dash lights do there checks & balances; but “OD/OFF” light immediately comes back on after the 2 sec check function.

Engine not even started and it’s put itself into Failsafe mode.

Key to run & start engine, OD/ Failsafe light remains on.

Being 2006, this mode still using Nissan Consult II software via an OBD type plug (but not OBD II software)

I have the Nisscan software and scan for code/faults; nothing. Nothing in TCM or ECU.

I can make it fault by unplugging things, so software to TCM comms work.

ECM and TCM resets don’t resolve; key off for 10, pedal dance and unplugging battery etc.

TCM was set away by MoFo and supposedly was perfect.

I have removed AT control valve and TCM.

Looked over TCM for cracked connections, loose items, electrical test conductors, look for corrosion etc. all perfect as far as I could see and test.

Electrical test solenoids (couldn’t mechanical test though), all in spec of resistance.

Looked over valve assembly, couldn’t see anything weird or noticeable. Tolerances is another level that I don’t have information to check against.

Cleaned filter and checked all mating/seal surfaces.

Reassembled, new fluid (old oil looked fine when removed), got a fault code during air purge when refilling but cleared and never came back once all air out.

BUT, stayed in Failsafe mode!!!!

I have checked electrical connector to AT, 12V there, grounds there, CAN there.

I have checked ground for resistance and even put in new bypass ground to be sure.

I have scoped the power & ground to see if there are voltage ripples, doesn’t seem so.

I will check all globes in car this weekend in case there’s an LED, some people report errors caused by them…

I have the service manual, but not much help as this situation is really strange as no fault codes, and no use going through detailed diagnostics of gear changes and such when don’t get that far.

One thing of note, the oil pressure plug on side of box right next to oil cooler in/out, no pressure, no flow and no pressure actually.

In reverse and D, there is supposed to be pressure at port.

Has me bit confused, is a solenoid not opening and causing not control pressure at all and therefore 4th gear is default due to this gearbox actually still having a solid selection rod for P/R/N/D, only 1,2,3,5 are controlled by electrical solenoids.

All Nissan and AT places say to change out AT box, $7k!!! But I think there’s a chance it may not have anything to do with AT and fault could remain so not paying them $7k.

I will change with wrecker box myself if it comes to that.

Meanwhile…

I have ordered a new TCM with solenoids, cheap one so see if it just wastes more cost in AT fluid to change out or if it does actually make difference.

Otherwise any other suggestions?

Other than swap out Ute for one that works…

 

[Dustyfeet]

Closing out this one too.

So, short story, TCM was faulty after all.

Long story, after exhausting all avenues I had to verify all prior assumptions I’d been told and start from the start.
I bought a used complete transmission from a 2008 D40, on off chance it was compatible.
Simple thing first, removed TCM and valve block from donor box, plugged into my Ute.
Turned key onto accessory and no OD/OFF fault!!!!!
So swapped TCM and valve blocks, left my box in.
Works fine now and I need to sell the other box (if someone has ok TCM but blown box/transfer case, message me).

So, spoke with MoFo tonight to let him know what fixed it (a promise when I bought the Ute).
He was annoyed that the guy who checked the computer obviously didn’t know what he was doing… all along TCM fault.

Case closed.