110 300Tdi Immobiliser!!!

My 110 is being a right pain at the moment, sometimes it starts and others it dont!!! So I then have to bypass it which is another pain.

The issue is the immobiliser. Everything else works fine alarm/engine etc.

I turn the the ignition key one click, two click, hold breath and starter either turns or doesn't.

Through various checks with my multimeter I know it's the immobiliser because I have got voltage where I need it.

I've tried arming/dsiarming alarm system with both fobs (3TXB), both of which have new batteries (indicator lights iluminate when disarming) and this makes no difference when it wont start.

I've reflowed all the joints on the spider's (AMR4889) PCB and it started fine after this (about a week ago) so I know a) no dry joints on PCB b) I didn't cook anything on the PCB (I didn't reflow the transistor of chip as they can be very heat sensitive).

Other than replacing the spider is there anything else that could be the problem, a relay or something else in this circuit, I haven't got a schematic of the circuit to run through.

I dont want to bypass it for insurance and obviously security reasons, I want to fix it.

As an aside not one person has said anything anytime Ive hotwired??? I know it's mine but!!

PM's appreciated for sensitive bits.

Anyone!

Maybe triggered an error code on the alarm ECU?

read through this, see if it helps: The Definitive Alarm Spider Post - LR4x4 - The Land Rover Forum

you may need to be a member to read the tech archives.

sorry, no actual experience of these things.

G

mmaatt25 said:

My 110 is being a right pain at the moment, sometimes it starts and others it dont!!! So I then have to bypass it which is another pain.

The issue is the immobiliser. Everything else works fine alarm/engine etc.

I turn the the ignition key one click, two click, hold breath and starter either turns or doesn't.

Through various checks with my multimeter I know it's the immobiliser because I have got voltage where I need it.

I've tried arming/dsiarming alarm system with both fobs (3TXB), both of which have new batteries (indicator lights iluminate when disarming) and this makes no difference when it wont start.

I've reflowed all the joints on the spider's (AMR4889) PCB and it started fine after this (about a week ago) so I know a) no dry joints on PCB b) I didn't cook anything on the PCB (I didn't reflow the transistor of chip as they can be very heat sensitive).

Other than replacing the spider is there anything else that could be the problem, a relay or something else in this circuit, I haven't got a schematic of the circuit to run through.

I dont want to bypass it for insurance and obviously security reasons, I want to fix it.

As an aside not one person has said anything anytime Ive hotwired??? I know it's mine but!!

PM's appreciated for sensitive bits.

Click to expand...

What do you mean by?

Through various checks with my multimeter I know it's the immobiliser because I have got voltage where I need it.

Click to expand...

What checks have you done and from where to where? I went out to a 300tdi the other day with an immobiliser fault. It also had an ignition switch fault too. Everytime you cranked the engine it dropped the feed to the fuel stop solenoid.

Have you made sure the small spade connection to the starter motor is good and clean. You did take the measurement from the male connector on the starter and NOT fro the female spade on the end of the wire to the starter motor I take it?

You could just pop down to your local main dealers and buy a spider bypass wire. They cost about £8

When wont start I've got no voltage at either the starter motor solenoid or the diesel pump fuel cut off solenoid.

You could just pop down to your local main dealers and buy a spider bypass wire. They cost about £8

Or I could just solder two jumpers for nothing on the spider, but that still doesn't get me anywhere near solving the problem and I'm not sure where I stand with insurance.

Is there an alarm ecu as well as the spider/ignition coil?

Thanks for the replies.

mmaatt25 said:

When wont start I've got no voltage at either the starter motor solenoid or the diesel pump fuel cut off solenoid.

You could just pop down to your local main dealers and buy a spider bypass wire. They cost about £8

Or I could just solder two jumpers for nothing on the spider, but that still doesn't get me anywhere near solving the problem and I'm not sure where I stand with insurance.

Is there an alarm ecu as well as the spider/ignition coil?

Thanks for the replies.

Click to expand...

What's the voltage like at the actual ignition switch when turned to each of the 3 positions?