Central Locking and Power Steering issue

Hi all,
I have looked at central locking treads, no resolve, I have looked at power steering threads no resolve, hence a new thread.

I need help (so does my car!) a 2005 Vogue with a strange issue. When approached she will only unlock the drives door and with the remote (any of the keys) and the button pops up half way on first press. On second press the button pops all the way up and passenger door opens with the button half way up and NO other door will unlock. The central locking button on the dash does nothing. If you attempt to drive like this there is NO power assistance to the steering.

However if you do drive like this for about a mile, stop turn all off, lock the doors with the remote then open again all is good, everything (locks, steering etc.) works 100%.

Now the quirk: If you press the tailgate release button first, once nothing happens, twice, occasionally thrice, the tailgate will release, then you can unlock all doors as normal with the remote, shut the tailgate and drive with full power assistance on the steering and the dashboard central locking button working as well.

Anyone got any ideas? Its defeating me.

Don't know about the 322 but the P38 c/l will play up if the tailgate button is faulty/dirty. A good clean and lub cures it, may work for your motor. Saint will be along soon, he's top of the class, soon to be made prefect.

I am very sorry I don't see the relevance in your reply, how can the tailgate that works, stop the central locking and power steering working - clearly I am missing something vital in the information offered.

I'd first be looking at communication on the K and P databuses...

K deals with a lot of the security and interconnection systems...

P is the Peripheral Databus and is used for short commands and not continuous data...i.e. 'Open Sunroof' or 'Lock the Door'

This document is quite a good read (BMW based, but if yours is a BMW derived L322 it is quite relevant), also RAVE has some good information on which bus does what!

Most common item in the K bus to fail and render it useless is the Headlamp levelling ECU, or one of the headlamp ECUs

Hi Saint,

Thank you, I will sit and have a read, the two issues of Power Steering and Central Locking are very clearly related as both work or don't work, never one or the other.

Hiya Saint,

Thank you, quick update; having read it, I don't have the kit to do the technical checks, but walked through the manual tests, press this button press that - get this result then the BUS is good. All good. That left either the interference from such as fitted mobile phones, after market or upgraded SATNAVs, don't have any of them. So its a voltage state of -Ve or +Ve, where to start!!! I tow her all wheels down and have the electrics set to work the lights of the RR from the tow vehicle, therefore on the front lower valance there is a standard 7 pin socket through which the power to the RR lights passes when the umbilical is connected. I opened that socket (not been used for couple of weeks) it was full of water. Cleaned out and dried - hey no more problems from last Thursday until last night. Now one in five uses of the remote has the same problem and the alarm goes off 'all on it's own - at 2 in the morning!!!' so there is something else lurking will keep you updated - but she is much better - again thank you.

v8twins said:

Hiya Saint,

Thank you, quick update; having read it, I don't have the kit to do the technical checks, but walked through the manual tests, press this button press that - get this result then the BUS is good. All good. That left either the interference from such as fitted mobile phones, after market or upgraded SATNAVs, don't have any of them. So its a voltage state of -Ve or +Ve, where to start!!! I tow her all wheels down and have the electrics set to work the lights of the RR from the tow vehicle, therefore on the front lower valance there is a standard 7 pin socket through which the power to the RR lights passes when the umbilical is connected. I opened that socket (not been used for couple of weeks) it was full of water. Cleaned out and dried - hey no more problems from last Thursday until last night. Now one in five uses of the remote has the same problem and the alarm goes off 'all on it's own - at 2 in the morning!!!' so there is something else lurking will keep you updated - but she is much better - again thank you.

Click to expand...

If the plug got wet, suspect corrosion between the pins.

Hi Datatek, long time no speak, how you keeping? That had dawned on me yesterday and I hope that is the case, I am working away this week and have the P38 with me, will check when I get home on Saturday. The same socket for the P38 is actually on a short lead that tucks behind the air filter when not in use, hangs out of the bonnet when in use, maybe time to down grade the L322 to the same idea!

Fingers crossed - removed the 7 pin socket and it was showing signs of rust on the rear, no real voltage corrosion. However swapped it for a new one, and in last 24 hours has been good - but not yet claiming to have fixed it - far too early. At the same time think I my have discovered why the alarm is randomly sounding - thanks to threads here. Have disconnected the bonnet alarm switch and that is behaving as well for 24 hours, so have just ordered a new one to replace it.

Oh well, nearly, it has worked well then suddenly it stopped working for no reason, except I replaced the old bonnet alarm switch with a new one! I have even taken it off again but she won't revert to working correctly

Keep looking......

Hi, I would check the tailgate release switch, this switch put a ground to the BCU to open the tailgate, if there is a partial short when not pressed it could cause problems with the opperation of the BCU which controls CDL functions and the Servotronic steering. I wouls also disconnect the tow socket for the time being.

Hi owl, wow did not know that, I had narrowed it down to a steady state of a voltage either -Ve or +Ve, as noted above. So are we talking the upper or lower half of the taile gate or both? I work away and the good lady has this car during the week (I have the P38) so can't check till the weekend, but it all fits well with my thinking. And yes we are home for a weekor two so will remove the socket from the wiring loom connection points thus full isolating it - but one item at a time, I will try the release switch(s) first.

tomcat59alan said:

Don't know about the 322 but the P38 c/l will play up if the tailgate button is faulty/dirty.

Click to expand...

Hi Tomcat59alan, yes you did suggest this at the beginning, very sorry for not perusing it but until owl's post I did not understand or see the relevance, now I do, thanks.....

The upper tailgate switch is the one that puts a ground to the BCU, the lower tailgate release relay ( which is in the rear fuse box) recieves a power supply from the BCU and is grounded through the switch back to the BCU. The upper one is the most likley as if the seal around the switch isn't 100 % the draft behind the car can cause water ingress too the contacts. We change many on F/L2 and Disco 3 though not many on L322. These things can be hard to find sometimes, I recently had a RR with puddle lights that wouldn't come on which turned out to be a slight short in the front interior light which confused the BCU although the interior lights worked perfectly.

Hi Owl, how do you replace the upper switch, I have taken the mounting to pieces and the switch is mouldered into the wiring loom of the entire unit that has the number plate lights and button for the releasing of the upper half of the tailgate.

I assume you have to replace the entire unit and wiring that runs through the tailgate?

I can’t find any one selling one either, I can find switches the for the P38 tailgate, the Range Rover Sport tailgate but NOT the upper half of the L322 tailgate, I can find them for the lower half.

Any guidance greatly accepted please.

Yes I think you have to change the complete thing. Some Land Rovers you can get just the switch and some only the complete assembly. A parts person is the best to ask.

Oh well this is getting interesting NOT: Tow socket removed, top and bottom tail gate switches disconnected, for testing before I jump in and replace them. All working fine - its even been on a diagnostic set (I don't know what type) and nothing found. Okay lets reconnect one of these at a time and see what causes the the issue. Did not have time to reconnect when it rained - yes rained and it stopped working correctly! So left it to dry out and its started working again now its a rained again and its not working, I have checked the obvious places for water ingress and anywhere there are electronic components (in the boot, under the seats, under the bonnet etc.) nothing - all dry. Anyone got any ideas as to what I am missing please?

Never played with an L322 but guessing:

Sunroof drains?
Door seals?
Window seals?
Pollen filters or anywhere air comes through from outside.

Hi,
Thank you; can discount:
Sunroof Drains (Checked!)
Door Seals (Checked!),

Window seals, that's an interesting one will look at this, this weekend, maybe - happy to be told not the case - is it possible water is affecting the door locks within the door(s) and causing this?
Pollen Filters, need to look at that this one.
Thanks

It is a Land Rover so anything is possible!