Hi everybody; I have a Freelander 1 Td4 which I love to bits; but which is severely testing my patience and resources. It has a shopping list of problems all fighting for my attention. I can’t afford to fix them all at once, so it’s a case of the ‘squeakiest wheel getting the grease’ at the moment.
One major problem is a reoccurring issue with the Immobiliser Control Unit. Quite frequently, and without any obvious provocation, it will start emitting a loud, continuous, and rapid, ‘clicking’ sound. When this happens, the vehicle will continue to run, but the instruments will ‘freeze’. This state will continue until I stop the vehicle and leave it for a few hours. On re-starting all is usually back to normal; with the exception that I will have lost ‘Trip’ data and an amber engine warning light will be on. This warning light generally persists for the next two or three re-starts and then disappears.
In an attempt to solve this problem I purchased a pre-used Immobiliser Control Unit from eBay (there were loads for sale so it seemed swapping them out must be common practice), and fitted it in place of my ‘faulty’ one (what i’m glossing over here is a description of the hours of heart-breaking, knuckle-skinning labour required to do this; but I will say that it prompted me to re-locate the control unit to a slightly more accessible location). Much to my delight, the remote central locking worked, and when I put the key in the ignition the instruments worked; but when I turned the key I was rewarded with absolutely nothing: no engine turning, no clicking solenoids; nothing.
So, after a friend of mine ‘re-touched’ some of the solders on the back of the pcb of my original ICU I put it back in. For a short while I thought the problem was fixed; but lately i’m back to the annoying rapid-fire clicking from the dashboard and frozen clocks again. It’s like Chinese water torture, and the more I try to ignore it the worse it gets. What niggles me is that these ICUs are still continually for sale on eBay; so I can’t believe that everybody who’s bought one has been as unsuccessful as me, or it would show up in the ‘feedback’.
The bottom line is that I can’t afford to have a Landrover dealer experiment at my expense. I’ve been financially disembowelled by main dealers too often to want to try that again; so I’m desperate to resolve this and the half a dozen others issues myself. If anyone has any advice I am all ears.

What age is your car and what was the part number or photo of the unit you replaced?

Manual or auto?

Hi td4van

Thank you for responding.

My vehicle is a Manual gearbox Td4 HSE on a 54 plate, registered in January 2005.

I was very careful to ensure I matched the part number (YWC-500261), as well as the vehicle model and year when ordering the replacement ICU. To my recollection, the only number that really differed on the two units was the Serial number.

You can't fit an immobilizer ECU from another vehicle, unless you change the key transponder and engine ECU too. The whole idea of the immobilizer is to secure the vehicle from being stolen, without having matching keys.

Also the remote locking is nothing to do with the immobilizer ECU. Locking is controlled by the CCU.

I suspect your issue isn't the immobilizer at all, but a CAN bus fault.

Is the clicking coming from the lower dash or could it be coming from the display binnacle?
Mike

Hi Mike
It’s definitely coming from the ICU. I think it’s the solenoid in there ‘cycling’.

And i’m whispering this to Nodge68 because I don’t want to appear stupid; but what’s a CAN bus? Have received and understood what you’re saying about how the immobiliser system works; but now I need a solution. Can this CAN bus be fixed, or, should I get a matching ICU, ECU and transponder set?

Canbus is the communication system. So all the wiring, units such as, ECU, CCU, ABS, and the display binnacle (which acts as a hub/ that's why I asked) all talk to each other. Unfortunately it does tend to talk bollox when a part goes tits up.
Mike

Your car won’t start as you need a matching set of immobiliser, key transponders and engine ecu.

Plus you need to make sure that they’re from a manual otherwise it won’t start as it won’t see a Park/neutral input from the auto box.

As Nodge said I suspect the issue isn’t the immobiliser but rather the CCU or the fuse/relay board under the steering wheel

Ok. Thanks guys; that gives me something else to look at. It looks like second hand fuse boards are cheap enough, and fairly straightforward to swap out, so i’ll give that a go.
I’ll let you know how I get on.
In the meantime, i’m still open to last minute thoughts and advice on this.