2003 freelander immobilised

Been asked to fault find on a mates 2003 freelander but it's really baffling me.

The car was a cheap trade in with a suspected knackered fuel pump but after this was replaced it refuses to run.

It will turn over and fire for a second but only after the FOB has been used to lock/unlock the doors.

If you try without using the lock unlock method it will not spark at all.

There are no fault codes coming up on the machine, impact switch has been checked, cam sensors changed and even swapped ecus so I'm at a loss and so is he!

Has anybody seen this before? I find it strange that the car will only fire after being locked and unlocked.

Is this a 1.8 petrol?

Immobilisation and remote locking are not linked on a 2003 assuming it's as it left the factory

It may of course have an aftermarket immobiliser setup somewhere

Yes 1.8 petrol

It has the old style FOB and separate key if that matters.

Think that means it's actually a 2002

The fob is separate from the key. The 1A chassis No onwards Freelander immobiliser transponder is in the key, not the fob.
If it runs for a second, then sounds like no fuel. Does the pump prime for about 10 seconds when the key is turned?
You can't swap the ECU as it's coded to the key. This will simply immobilise the engine completely. Do you here a chime and see a flashing light on the dash. If not, the immobiliser isn't active.

Right, spent a couple of hours on this with my autel diagnostics machine and I'm absolutely baffled!

At no point could I get a chime from the dash.

You could swap the ECU and the car will start RUN off the key for 1 or 2 seconds and then die and turn over.

Fuel pump primes, car doesnt show any faults on the autel.

The autel allows you to program PLIPS, so I tried reprogramming different plips to the car with both ecus but still no joy.

I also tried doing all throttle position resets etc just in case.

The last straw was watching the immobiliser on the autel. at no point will the immobiliser turn off. it will always remain IMMOBILISED throughout all this.

If it runs for a short time, then it's immobilised. The ECU and immobiliser take a couple of seconds running before it realises that something is wrong. Have you checked the transponder coil in the ignition lock? It sounds like the immobiliser ECU isn't seeing the key. You will need to put the correct engine ECU in it too

yea, i thought it may be so Ive advised him to change the ring.

theres no was the ecu could fry and knacker the immobiliser part?

also, did dismantle the ring and it looks perfect but who knows

haggis said:

also, did dismantle the ring and it looks perfect but who knows

Click to expand...

Have you done a resistance check on it?

Nope, just thought it would be as simple as a broken wire

The transponder coil is normally pretty reliable but I have seen a couple fail over the years.
Do a resistance check on the ring connections.
Here's how the system works, according to the manual.

Well he's off to buy another ring for it today. Failing that I think it'll be getting scrapped

Cost to reward just isn't good enough if it's anything else

haggis said:

Well he's off to buy another ring for it today. Failing that I think it'll be getting scrapped

Cost to reward just isn't good enough if it's anything else

Click to expand...

The only other thing I can think of is the rolling code sequence has gone out of phase.
It may need synchronisation between the immobiliser and engine ECU.

I couldnt see anything like that on the autel. Ive heard about that before on BMWs when the battery goes flat.

Dont think my machine can do that, it can do all the service functions and code keys etc but no RR sync

I might be wrong here but have you replaced the battery in the key fob and re-calibrated it? Stand beside the car and push the unlock 5 times?
Worth a try