Greetings Forum,

I'm getting more frequent fail safe "no starts" while throwing the P 0705 code. It was initially seldom and turning ignition off would usually reset the system and then I could start. I've read here on the forum that this usually indicates a failing Neutral Safety Switch.
I've tried adjusting and cleaning the transmission control switch (transmission linear switch) and shifter cable attached to the shifter with no luck. I want to try changing the Neutral Safety Switch but have looked in the manuals and checked the forum for it's location to no avail. I looked on the transmission where the 5 speeds is mounted but nothing there. Hate to sound like a noob,but where the heck is it??
The car is a 2003 XKR, 200K and of course the ZF 6HP26.
As always, TIA

ET

 

range switch is in the tcm. hall effect reads off the manual valve

 

Thanks Xalty

 

I forgot to mention that the fail safe only happens when the car is fully warmed up and I've been driving it for awhile. When cold or cool, it never happens and runs perfectly. I do have a freshly rebuilt tranny, so the transmission guy will check it out. I told him I still think it's just the Neutral Safety Switch. I'm throwing in the towel on this one and dropping it off today at the shop. My transmission guy is sharp as a tack. You could eat off his shop floor.
He has a reputable valve body rebuild shop.
He told me the units are no longer built and hard to get, so this rebuild guy might be the answer.

 

P0705 is the range / gear position switch, as xalty asserts:



Hopefully your transmission guy can help. Take a look at this thread from 2006silverrr onone of the LandRover forums:
https://www.rangerovers.net/threads/...-fault.354149/

 

Thanks for the link michaelh. Sounds familiar but my problem is only the fail safe mode on start now. My tranny needed the rebuild. It had been slipping for awhile with mis shifts, then limp and a bunch of "7" codes. It was shot after 198K
It's operating perfectly now, barring the start fail safe and limp mode. Hopefully this service will cure it all 🤞

 

So you get the P0705 by following the monitoring conditions as described in the DTC list entry above?

 

No, I can't induce the failure, it only happens at start up.. Car runs perfectly, even with P to 2 selections multiple times, (as above in the monitoring conditions) once it's started. It starts and runs perfectly when cold or cool. The problem is when I try to start after it is warmed up. Frequently goes into fail safe and the car will not crank. Turning the key off and manipulating the shifter would usually let it start. But the problem has intensified with multiple attempts to do this. Now it is throwing the P0705 code as soon as the key is turned to ACC. If it does start it is immediately in limp, with the hard shifts and locked into 3rd gear, I think. Then I clear the codes with my reader software and try to start over and over. The problem was getting worse and I knew I'd get stranded pretty soon. Pretty sure I need a TCU and/or a neutral safety switch. Those weren't included in my tranny rebuild, which I didn't know. He did all the hardware, but not the software...

 

Have you checked the connector at the mechatronics sleeve? That connector can be tricky to put back on after maintenance. There are specific directions to make it all fit together. The connector insert cannot be twisted. The securing collar needs to come to a resting position a specific distance from the case. There are circumstances where the pins in the connector (harness side) get pushed back and result in poor/broken connections. The connector could also be contaminated with transmission fluid. This connector of course includes CAN bus lines, so perfection is your friend here. This connector is towards the back of the transmission, so sort of center to the car. Once the car is safely lifted, it is not that hard to reach and inspect with a good light and a mechanics mirror. Might be a good $0 check to perform.

Best of luck, keep us posted.

PS: thectsc.com has an FAQ section with great illustrations.

 

I specifically asked the AAMCO guy to make sure it was seated properly at my last trans service over a year ago. No problem with electronic indications, but continued poor shifts, mis shifts, multiple "7" codes and limp mode . After pulling over and shutting down, everything would reset. I knew the transmission was tired and was sick of babying it and having to stop, shut down and restart to continue driving. The tranny rebuild fixed all the poor shifting, mis shifts and limp mode while driving. That was all mechanical from a worn transmission. Great transmission guy, very knowledgable, with a shop full of Rovers, Mercedes, Beemers and Jags. What a cash cow! LOL
This prob now is all electronic when the car is not moving. Fail safe and no start when the tranny is hot. I'm just not sure if it is the TCU or neutral safety switch that is bad. I'd rather replace them both and not have to deal with it anymore. Unfortunately, it looks like every rebuilt TCU comes from China....
Maybe it is just the connector, but the "no start" was happening more and more frequently. It went from rarely not starting to regularly not starting. But once again, the problem and fail safe only happens at start. I will keep advising the board here, however....

 

When I looked for 03 XKR ZF6HP26 neutral safety switches, they show up on line as a switch with a pigtail, externally mounted on the gearbox, like on the Mercedes 5HP. When I asked my transmission guy whether I need a TCU and/or a neutral switch, he showed me a TCU in the shop. The neutral safety switch is integrated into the TCU and looks nothing like what I see on my searchs. He explained it is one whole unit, not separate components.
Can anyone give me a "Cliff Notes" explanation please?

 

Good Morning Forum,

I'm officially in the Jaguar "Groundhog Day" movie.

MY 2003 XKR Convert with the ZF 6HP26 has been sitting in the transmission shop for 3 weeks. To refresh the story, it has a newly rebuilt transmission from this shop, but right after the rebuild, started to failsafe and not start when warmed up.

The transmission guy said it needs a new or rebuilt TCU / Conductor plate, which wasn't included in the rebuild. It contains the position sensor / neutral safety sensor as an integral part and something is bad, because of age, use, or the connections or soldering Unfortunately the neutral safety switch is integral to the TCU / conductor plate, unlike the Mercedes 5 speed where it is a separate switch.

He said they are almost impossible to find. He's tried to source a new, rebuilt or used unit everywhere with no luck, junkyards, transmission suppliers and rebuilders, Jaguar and ZF (they told him 6 month lead time and $2000).

I see rebuilt TCU / Conductor plates on Ebay exclusively from China. Will these work??

Where the heck do I / he source one of these things from. I don't want to wait 6 months!

 

used tcm or have the range switch repair kit installed

if it’s a direct match from an xkr 4.2 sc no programming

if it comes from anything else it needs to from an 05 and down and then configured to the car

 

I appreciate it Xalty...