[QUOTE=DakotaTravler;688101]Fuel pressure fault? Code P081C is a park input circuit failure. It is a problem with the "neutral safety switch". Reminds me of my Mark VIII days, very common issue.

Anyway, turn the headlights on manually before starting the truck as see if you have the same issue.

I Turn my headlight on manually, I don't get the Transmission Fault when I put it in drive

 

I also Have P081 c-00 Park input circuit, I get the Fault when I put it in drive every time except when I Manually turn headlights on before I start the Truck, any help would be greatly appreciated.

 

If turning the headlights on first works, then you have a voltage supply issue to the shifter. With headlights on, there is a second source for power so the fault goes away. Dont ask me, I did not design this sorta of insanity. But it means you either need a new shifter assembly or there is a problem with wiring, relay, fuse, etc. I dont know for sure, the headlight trick is more for a simple diagnosis or in case the vehicle is stuck in park one can now get it moving.

 

Thank you for you’re help,
Does anyone have the electric schematics for the shifter harness.

 

 

Thanks guys, I had Limp mode come on today morning, I got the computer to check for the error code, landed on this forum and your advice worked perfectly for me. Headlights on and we are good to go for now till we get the shifter checked (wiring, relay and fuse).
thanks again

 

Hey Dakota, I'm about to drive off a cliff!!!! I also have the P081C-64. Turn on headlights and can operate LR4 but no sport shift, fault comes up once in "D" -Gearbox fault. I've looked at the wiring diagram and cant figure out where this additional power supply comes from or what part of the gearshift it powers? The headlight test therefore proves its wiring and not mechatronics? My wiring is all good no corrosion, checked fuses but relays are unknown, no info? Will do resistance test today, mechatronics plug to gearshift plug.
Any additional info would be greatly appreciated!!!!
Cheers Greg

 

I am not sure how they exactly made this thing so turning on headlights allows one to shift. I almost think that was not by design, not sure. There are two 5 amp fuses, 33 & 44, in the central junction box. At lest on an LR3. One is alway shot, one is hot with in key position II/run. The only other source is through illumination, so if there is some sorta crossover I think it would be inside the shifter itself. Check those fuses otherwise you pretty much have to plan on spending $250 for a new shifter assembly or risk getting a used one. I dont think they have to be programed.

 

Turns out that headlights make no difference, it still starts shifts and drives, however when D is selected gearbox fault comes up....That cliffs looking good

 

Well you also have an LR4 which is not exactly like an LR3. I forget what a trans capacitor can do to an LR4, I think when it fails it prevents shifting too but not sure if it throws a code. On an LR3 the capacitor can simply be unplugged. On an LR4 I think it must be replaced. But I am not certain this is your issue, again, because I am not sure if a blown capacitor throws a code.