Car won't start. Pulled some codes

[Acuwar]

I got
P0851 - Park/Neutral switch - input circuit low
U0101 - Low communication with TCM

Any help, please.

 

[tlt]

Brake light switch, battery voltage low? It doesn't seem like that would cause it to not start though, and this is an unscientific guess.

 

[Acuwar]

Brake light switch, battery voltage low? It doesn't seem like that would cause it to not start though, and this is an unscientific guess.

Thanks for any help tlt.

Had the battery checked and LR and an auto store. Both said it's fine and kept the charge from auto store.
Changed brake light switch just in case.

 

[Acuwar]

got a new battery just in case.
truck is still spitting out the same codes and refuses to start

P0851 - Park / Neutral switch input circuit low
&
U0101 - Lost communication with TCM

thanks anyone!

 

[CMGRover]

Interesting that they are both tranny related.

That switch one I'd think should be easier to sort out, just get a new neutral switch I think.

The TCM one is interesting...
http://engine-codes.com/u0101.html

Is their any signs of mice anywhere that could have chewed wires?

 

[RoverGuy7]

The P/N switch is built into the valve body.

What do the PRND lights do(by the shifter, not on the dash)? Lit up correctly(indicator, not illumination) all the time; only when key on, not running; only when running; does it change with headlights switched on?

 

[zpbassham]

I have the same issue 2006 RR HSE. Had transmission filter, fluid and seals replaced. No help. Drives smooth for about 10 miles, and "Bong" Transmission fault. All functions disabled and within a minute, "limp mode". Help!

p0851, park/neutral switch input - circuit low
p0705, Range sensor A low input
u2016, control module main software
and many other U codes.

I think the mechatronics or the software is bad.

Thoughts???

"My wife hates the RR"

 

[zpbassham]

I have codes p0851 and P0705. I was told by 2 land rover mechs that it sounds like transmission failure because the full-size HSE models don't usually give these codes. The newer sport models are usually remedied by replacing TCM. I am hoping I can get this figured out. The transmission is smooth until limp mode after 15 miles or so. Any help is appreciated. I have only had RR for 3 months. Cant drive it and I can't imagine dumping thousands more into it.

 

[zpbassham]

Any fix for this?

 

[Houm_WA]

Have you tried the Range Rover forum?