XYZ Inhibitor Change Selector switch on JATCO box

Hi, can anyone give me some advice on the removal of the XYZ Inhibitor Change Selector switch from the top of my JATCO auto box on my 2005 TD4. I've removed the two studs and the assembly turns but will not come off. Don't want to break it before I get a replacement one! I assume it pulls off?

It just pulls out. The O ring sticks solid sometimes. It's not a true XYZ switch though, just a simple rotary switch.
Normally it actually shouldn't be touched as it needs a special alignment tool to set it in the correct position.

Thanks for the reply!
From what I can see, the alignment tool is for when you replace the cable to the shifter inside isn't it? The switch has alignment marks (2 dots) that should be in line when in neutral. The thing has some adjustment built in simply to align the dots. I think I have a corroded track on it when it sits in park as I get error messages. I'm getting a replacement one from eBay and intend to try it and then take the old one to bits to confirm the bad track idea.
But at the moment it won't pull off!
I dis-inclined to force it off and risk breaking the plastic until I have a replacement one to put on!

I've one in my spares box at home, which I can take a picture of if it helps.

Have you checked the sensors at the gear stick? Those can play up too, and go out of sync with the box switch, giving errors.

What I get is the HDC warning light on and F4 error message flashing on the LCD display when it's in park and the ignition turns on. Plus it says it's in Sport mode in the LCD and on the shifter display. But NO other warning lights. I had it plugged into a LR diagnostic which flagged up the start inhibitor switch.
If I turn the ignition off and move the shifter and then turn the ignition on it stops!
BUT, strangely it only does it when the engine is hot, never when I jump into it in the morning!
Last night I tweaked the position of the switch by rotating it slightly. No warnings so far.
Which is why I think it may be a bad bit of track on the switch.
Sound logical?

Drives normally even with warnings on!

I get the HDC light and F4 if I move the gear selector a bit too close to 4 from the D detent. I believe this is caused by the selector sensors being out alignment due to wear in the selector detents. I just have to make sure the gear is locked in the detent firmly, and the fault doesn't occur.

Sounds similar!
I only bought the vehicle early April and have a full LR service history with receipts.
Four years ago the guy was charged £450 for a 'new gear selector mechanism' because he could not get it into Sport mode.
So I reckon the shifter and sensors in there are newish.
I'll let you know if changing the inhibitor mechanism stops the fault!
Thanks for your help!

If the led's by the gear lever are wrong then it's either a problem with the switch ont top of the auto or the barrel connector or wiring harness which carry the selector position signals away from the gearbox.

In your case it won't be caused by the position of the selector cable as it works ok at other times.

Thanks for the reply.
It only occurs when the engine and gearbox is hot, which makes me think it's a duff track on the rotary switch and when the grease in there gets hot it changes resistance.
Anyway I have a switch with loom back to the barrel connection coming today. When I fit it I'll remove the battery tray and check the loom right back to the connector in the ECU unit.

Well, to update you....
I got the replacement selector today so took the old one off and took it to bits.
Wasn't in bad condition, but was very surprised the see dialectric grease completely covering everything, including the rotary contacts.
From my limited knowledge grease shouldn't be on the contacts as it's an insulator.
So I checked inside the replacement one and that was the same!
Cleaned it out and replaced with dialectric grease just on the rear of the rotor arm and where bits rub.
Assembled it all and tested it and it's exactly the same as before!!

I'm now thinking it's either a problem with the wiring that comes back to the shifter or the shifter itself.
I'd appreciate any other ideas!

digitalcut said:

I'm now thinking it's either a problem with the wiring that comes back to the shifter or the shifter itself.
I'd appreciate any other ideas!

Click to expand...

Did you see this? That I wrote on Friday?

Nodge68 said:

Have you checked the sensors at the gear stick? Those can play up too, and go out of sync with the box switch, giving errors.

Click to expand...

Hi mate. No I haven't.
How do you do that?
Sounds like it could be that. I reckon the sensor that says it's flicked across to Sport mode could be the one.
I know how to get the gear stick off.

Do the led's by the gear stick display the correct position for the gear lever? They're powered via the switch int top of the auto and wiring harness. It is the place to start looking when the gear lever position is reported incorrectly. Far easier to diagnose the led's first if they're illuminated pattern doesn't match the gear lever position.

Hi mate,
What I get is the yellow HDC warning light and F4 error message flashing on the LCD display when it's in park and the ignition turns on. Plus it says it's in 'Sport' mode in the LCD and on the LED shifter display. At the same time, the 'P' LED is on not the 'D' LED. There are NO other warning lights.
This generally happens after a drive when hot then you stop, leave it for a few mins and try to start.
As I say, it drives perfect with the error messages up.
If you turn the ignition off move the shifter and then restart, the message disappears.
Photos here of the errors if you are interested:
https://www.dropbox.com/sh/3fn9qe4fg9xz1br/AADA2DpHiLnnfO9KjzbtuEF7a?dl=0

digitalcut said:

Hi mate,
What I get is the yellow HDC warning light and F4 error message flashing on the LCD display when it's in park and the ignition turns on. Plus it says it's in 'Sport' mode in the LCD and on the LED shifter display. At the same time, the 'P' LED is on not the 'D' LED. There are NO other warning lights.
This generally happens after a drive when hot then you stop, leave it for a few mins and try to start.
As I say, it drives perfect with the error messages up.
If you turn the ignition off move the shifter and then restart, the message disappears.
Photos here of the errors if you are interested:
https://www.dropbox.com/sh/3fn9qe4fg9xz1br/AADA2DpHiLnnfO9KjzbtuEF7a?dl=0

Click to expand...

When it's displaying the fault... if you move the lever to all other positions, do the led's still give the correct position indication?

If it does then look at the PCB next to the gear lever. Bottom right cable below connects to it.

The error message is confirming the lever sensor position reports different to the switch position ont top of the auto. The two sources of info are continuously compared.


DSCN1889 hGS175j

If the gear stick sensor is sensing the lever is in sport, then it'll show a fault when in park, as this can't happen. I suspect your problem is the same as mine, and is to do with the lever sensors, not the box position switch. Mine also gives the F4, if I don't make sure the gear lever is locked correctly in D. Mine also doesn't go into sport all the time, possibly due to the same reason I'm getting F4. It's on my to do list, but wanted to get my box solenoids working correctly, before tackling the lever issues.

Thanks both of you!
I was sat in a car park for the last hour as a job was cancelled so I pulled off the shifter cover to see the sensor. I worked out that the lower connector at the rear does the sport mode, so thanks for confirming it with a photo!
I've left the sensor unplugged for the moment, so it will not activate Sport mode, I'll try driving it like that to see if the error appears.
As I say, it doesn't appear all the time.
I'm also wondering about if the wire to that connector go directly to the inhibitor switch on top of the gearbox or via the box ECU. Might be a problem with one of them.
Slowly i'm getting there I reckon! Just lucky mine drives as normal with the fault.

OK, I've driven it for a day with the Sport mode sensor unplugged and so far no errors!
OK, so I can't access Sport mode, but no big deal to me as it has a remap anyway and don't need it.
Can you change that sensor without changing the whole shifter unit?
And are there any other bad points to leaving the thing disconnected?

digitalcut said:

OK, I've driven it for a day with the Sport mode sensor unplugged and so far no errors!
OK, so I can't access Sport mode, but no big deal to me as it has a remap anyway and don't need it.
Can you change that sensor without changing the whole shifter unit?
And are there any other bad points to leaving the thing disconnected?

Click to expand...

Sorry I can't remember how the sensor comes out. Is it still working like this... indicating you've found the fault by process of elimination?