Immobiliser Issue...possibly?

Hello,

my Defender 110 Td5 refused to start yesterday morning - all the instruments were fine, the heater coil light came on and went out OK, but when I went to start it, the starter solenoid gave a good clunk, but the starter didn't turn.

I assumed I had a failed battery, so attached jump leads to it from my van and it started fine - problem solved I thought.

I drove twenty odd miles in it, stopped the engine, went to start it again and nothing - the same solenoid clunk but no starter action. I was pretty certain it wasn't the battery by this point, so I assumed I had a dodgy starter and went at it with the old hitting-it-with-a hammer-while-somebody-turns-the-key trick...but with no luck.

Out of desperation, I just tried turning the key a few times and on the third attempt, it started fine, although with a bit of a cough and the engine light came on. I read the codes (later, not while it was running) and the ECU had flagged a "high speed crank sync lost" error, but I think this was secondary to the actual problem and just flagged because the starter tried to cut out while the engine was still starting...which suggests to me that it's not just the starter being disabled by whatever the actual problem is.

I drove it another 60 miles, got home, stopped the engine and tried to start it again - no problems. Tried it again this morning and just got the solenoid clunk. I tried immobilising and then de-immobilising it with the alarm fob, tried the starter again and it started fine. I then moved it fifty yards, stopped it, tried to start again and just got the solenoid clunk...

The ECU isn't logging any errors, but I've only got a simple code reader and can't access the alarm/immobiliser (assuming you actually can). Does this sound like an immobiliser issue? Has anybody else had the same problem and, if so, how did you fix it? Is it possible to have the immobiliser disabled by somebody (e.g. an LR dealer) with better diagnostic kit then I've got?

Clearly my Defender can smell the snow coming and doesn't want any of it...

Thanks for any help

Start eliminating earth problems first. Costs nothing to connect your jump leads to the earth terminal on the battery then to a solid part of the engine see if this has any improvement if so it's an earth problem if not we need to look elsewhere.
Tim

Hi Tim,

thanks for that - good advice. I think, perhaps, I was jumping to the worst-case scenario a little early!

I get the same behaviour with the engine earthed via a lead direct from the battery - sometimes it starts first try, sometimes after three or four attempts.

As I can hear the solenoid engaging, I'm inclined to think it probably is the starter or the solenoid contacts. The starter has an uninterrupted feed direct from the battery positive, so presumably the immobiliser can't prevent it from turning if the solenoid is engaging. The thing that made me so certain it wasn't the starter in the first place was that I fitted a new one only two years ago...but I bet it was Britpart, so I shouldn't be surprised it's given up so quickly...

I see you can buy a solenoid rebuild kit from various sources - I've never tried changing just the solenoid contacts without removing the motor before; do you know if it's any easier than the expletive-laden job of removing the starter?

Thanks for your help

eprothe said:

Hi Tim,

thanks for that - good advice. I think, perhaps, I was jumping to the worst-case scenario a little early!

I get the same behaviour with the engine earthed via a lead direct from the battery - sometimes it starts first try, sometimes after three or four attempts.

As I can hear the solenoid engaging, I'm inclined to think it probably is the starter or the solenoid contacts. The starter has an uninterrupted feed direct from the battery positive, so presumably the immobiliser can't prevent it from turning if the solenoid is engaging. The thing that made me so certain it wasn't the starter in the first place was that I fitted a new one only two years ago...but I bet it was Britpart, so I shouldn't be surprised it's given up so quickly...

I see you can buy a solenoid rebuild kit from various sources - I've never tried changing just the solenoid contacts without removing the motor before; do you know if it's any easier than the expletive-laden job of removing the starter?

Thanks for your help

Click to expand...

I would recommend this one, some of the cheaper kits have smaller contacts.
https://x8r.co.uk/land-rover-discov...-denso-solenoid-starter-motor-repair-kit.html

The starter is not that bad if you undo the top nut last and pull the starter out as you undo it.
Get an extension of the right length and it should be a simple job to remove.

Cheers

Hi mate - I had exactly the same issue. I chased everything down. I replaced the solenoid on my starter, then I changed the starter, the battery and even the cable from the starter to the battery. It was the small connector to the starter, it had become corroded. I just replaced the spade and its been fine ever since (probably jinxed it now).

Cheers

Hello again,

thanks all for your help and advice.

On the likelihood that the starter I fitted two years ago came in a low-quality blue bag, I decided to just fit a new starter complete - from Hella this time.

I can confirm that changing the starter on a Td5 is a massive pain in the postern; I had to remove the air inlet pipe from the wing-fixing and take the engine cover off to even see the top bolt, then find a socket-set with a thin handle, as my usual one was too fat to clear the back of the starter and the engine mount. If you are one with the force and the force is with you, I dare say you can remove the top-bolt from underneath, but I had to do it from the top, where I could see what I was doing by looking down through the inlet manifold.

The old starter has a bit of corrosion on the bottom of it and the plastic around the positive terminal has cracked, but I've not taken it apart to see what the issue is...corroded solenoid contacts, almost certainly. I've so far started with the new starter first time, five times in a row, so let's hope that's sorted it...

Thanks

eprothe said:

Hello again,

thanks all for your help and advice.

On the likelihood that the starter I fitted two years ago came in a low-quality blue bag, I decided to just fit a new starter complete - from Hella this time.

I can confirm that changing the starter on a Td5 is a massive pain in the postern; I had to remove the air inlet pipe from the wing-fixing and take the engine cover off to even see the top bolt, then find a socket-set with a thin handle, as my usual one was too fat to clear the back of the starter and the engine mount. If you are one with the force and the force is with you, I dare say you can remove the top-bolt from underneath, but I had to do it from the top, where I could see what I was doing by looking down through the inlet manifold.

The old starter has a bit of corrosion on the bottom of it and the plastic around the positive terminal has cracked, but I've not taken it apart to see what the issue is...corroded solenoid contacts, almost certainly. I've so far started with the new starter first time, five times in a row, so let's hope that's sorted it...

Thanks

Click to expand...

Failing that, check the wiring at the back of the ignition switch