I have a 51plate Freelander td4 BMW engine, I've had it one year and feel like burning it!
My immobiliser system keeps generating the same fault, car runs great for a few months then I go to start it and although the fob works, light goes out in dashboard the engine just turns and won't start. The first time it happened a month after buying it the land rover specific code which seems to be top secret told the dealer it could be one of 5 immobiliser components at fault, he immediately reneged on his so called 3month warranty and I ended up having to fix it myself. By replacing fob, key, complete ignition barrel, 2 components behind dash and ECU it started and run great for about 6months. October same problem same code same resolve, its now done the same again. There are so many of the kits for sale on ebay this has to be a common problem but land rover say no. Does anyone have any answers how to fix or bypass immobiliser or a box of matches?

Is the code so top secret that you can't share it with us?

If the light goes out and the engine turns over, it isn't immobilised - or at least the component that control immobilisation do not think the car should be imobilised.

I do not know how imobilisation works on the TD4, but on the Rover engines, the CCU/immobilisation unit determines in immobilisation should occur or not and controls whether the starter motor turns.

Secondary to this is the engine ECU which will also control whether fuel should be supplied to the cylinders. If it is an immobilisation issue, and unless the starter solenoid wiring has been changed to a fixed earth (which the immobilisation light on the dash going out suggests not), it will be this secondary bit that has got confused. The ECU communicates to the CCU to determine whether this secondary immobilisation should occur - if you have replaced both these bits and are still getting problems - then the issue must be in the wiring between the 2. I would suggest you have a look in the Rave manual at the wiring diagrams and check the relevant wiring.

However, are you sure it is an immobilisation issue? There are a few things on the TD4 that give similar symptoms - ie not starting! The HPFP Pressure regulator O ring, fuel pressure sensor/injector (always forget which it is) loom. Less likely to be the O ring in this instance - but if you've been working on the electronic bits, the loom will have been moved/pushed/leant on etc and could have completed/lost its circuit.

It's the BMW system on my car, land rover mechanics confirmed the engine would turn if still immobilized. The code was E43, land rover would not say anymore to the garage that recovered my car than its an immobiliser fault and they wanted the vehicle brought to them. They quoted £650 for one component and £35 an hour to work on it, after doing some calling around and research one land rover agent advised to replace the components I listed above with 2nd hand he even mentioned ebay. If you search there are good number for sale some include the drivers door lock and fuel cap. There is a breakers yard near to me that specialize in land rover spares who actually remove all units from scrapped freelanders and sell them straight off the shelf as repair kits, they tell me they are a common request. I've had the fuel system checked as that was offered as a first cause but it checks out ok, when the car runs it gives no performance issues.

E43 does not sound like the sort of code returned by diagnostics on Freelanders.

The TD4 uses a Bosch Engine Management system. A search for E43 and Bosch only brings up Washing Machines!

The reason these parts are sold is because they are all coded together for "security" reasons - ie the ECU and CCU are coded matching pairs so you need to swap both, then the keys are coded to the CCU so you need to replace the keys as well, then the locks need replacing etc. Some of the parts can be recoded using diagnostics equipment.

However, it is fairly obvious that what ever has been replaced on your car is not what is causing the problem! So replacing it again will not fix it.

I'm sure something like the Hawkeye or Lynx diagnostics will show if your engine's ECU is immobilised. I doubt whether the cheaper i930 and pscans will. I may be wrong on both accounts there - maybe someone with the kit and a TD4 can confirm. If you see a setting that makes it look like the ECU is immobilised - check it on another (working) TD4 to make sure the diagnostic is different!

Before I do anything else, I would want to see categorical proof that the ECU is immobilised - just because LR said it was on the first error, does not necessarily mean it is now or ever was! If it is immobilised, forget about all the parts you have replaced - just consider all the other bits in the immobilisation circuit that have not been replaced - this may simply be the loom and as I say you'll need to check it out there may be a faulty wire somewhere, it may even be the diagnostics socket as I believe this is on the "network" on the Rover systems. I say this, but I suppose you could have a faulty alternator that is frying your ECUs.

Until you can see that the ECU is immobilised though, I would not assume that it is. Indeed you've replaced all the parts a number of times, so unless it is the wiring, it does look like its something else.

Hi Ken, having done a load of research into immob on TD4 - GG (above) has presented the workings well. If the key chip or 'start' immobiliser part is activated the car won't turn over at all when key is turned. If the ECU doesn't get the correct feed then it turns over but won't start. Again wise advice to check other basics first - I can't believe that your 2001 Freelander has a different 'BMW' system to the rest of the production !!! E43 is meaningless in terms of a TD4 fault code.

Connecting a Carsoft or Hawkeye will give you some data - like fuel pressure etc and it may be something simple.

Just as an informed 'guess' when it won't start try tapping the LP fuel pump (pass side engine bay near scuttle - behind battery) this is the thinner or 2 cylinders with a 2 pin plug in the top. It may just be an aged fuel pump. I have had this and it is very intermittent.

Without doing some more test I would spend no more money with LR !!!

Let us know how you get on............

It sounds like an engine problem. It's nothing to do with the immobiliser itself. It cranks over, therefore the immobiliser is allowing this to happen. It could be a wiring fault on the ECU to immobiliser coms bus. That would need scoping to find out.
I suspect it's a non immobiliser issue with the engine sensors though.
As said. The FL TD4 isn't a BMW system. It's actually a Rover system which is tried, tested and generally very reliable. If it does fail, it normally fails to crank.
You need to get proper codes read. E43 is worthless as a diagnostic code.