Had my lovely little red S1 serviced, MOT’d, sports CAT’d and generally taken care of and had a lovely drive back to London from darkest Cornwall.
Since then haven’t been able to get her to start
Key goes in & turn to stage I, pump primes, key fob depressed (alarm indicator light response), turn key to stage II … nothing!
Disconnected & reconnected battery (after a few minutes), checked all the fuses, gave all the wiring a cursory ‘once over’ and am now online looking for possible next steps.
It appears that one being, try by-passing the immobiliser?
Can someone PM me instructions for trying this please as I see this question has been asked before?
Update: I’ve been advised that if the fuel pump is being primed then it’s not the immobiliser (as the immobiliser wouldn’t permit it) - comments anyone?
Thanks All (Richard for giving me details for running a bypass),
I saw the eliseparts ‘block’ and may well end up getting one … I just wanted to know how to jerry-rig the bypass - as it’s just bridging two connections - so I can eliminate the immobiliser as a possible cause (or identify it as the cause … whichever).
I’ve established that there is no current going to the starter motor (the small control cable NOT the main cables) when the key is turned - so that’s either the relays, cables, or immobiliser (still). Before I start buying relays to swap out & test want to be sure on the immobiliser front.
If you have correctly bypassed the immobiliser and the fault still exists, then it can’t be the immobiliser, in which case it’s likely to be the cranking relay, which I think is the middle one of the block of three on the bulkhead.
Well after a few skinned knuckles managed to get to the immobiliser connector block, bridged the appropriate cables, and hey-presto car bursts into life
So … questions:
Does the alarm still secure the car in the same way (minus the immobiliser functions of course)? ie Doors opening/closing sounding the siren etc now that I’ve short-circuited the immobiliser unit?
If I remove the bridge on the connector block is the car protected in the same way as the immobiliser would? ie No starter motor current etc.
I’ve ordered the elisepart jumper block and plan to remove it whenever I leave the car parked … will it afford me a similar level of thief protection to the immobiliser unit?
[quote=sleepmonster]Well after a few skinned knuckles managed to get to the immobiliser connector block, bridged the appropriate cables, and hey-presto car bursts into life
So … questions:
Does the alarm still secure the car in the same way (minus the immobiliser functions of course)? ie Doors opening/closing sounding the siren etc now that I’ve short-circuited the immobiliser unit?
[color:#3366FF]Yes the alarm should still work, but only one way to find out, arm it with the alarm and then open the door[/color]
If I remove the bridge on the connector block is the car protected in the same way as the immobiliser would? ie No starter motor current etc.
[color:#3366FF]If it needs the block to start the car then i would say its 100% that the vehicle is fully imobilised without it. [/color]
I’ve ordered the elisepart jumper block and plan to remove it whenever I leave the car parked … will it afford me a similar level of thief protection to the immobiliser unit? [color:#3366FF]Same answer as above [/color][/quote]
Has anyone repaired their immobiliser, looking at the wiring diagram it looks like it would be a relay inside the unit that has gone. I may have a similar issue, but want to keep the immobiliser functioning. Some times when you get these electronics out, they are cased in an epoxy.
There are a load of broken ones out there, so if someone could fix them that would be great. As you say, it is probably just an internal relay or something simple. I’ve lost count of the number of people I have PM’d to tell them how to ‘get around’ the immobiliser
Some time ago I stripped one down to see if it could be repaired, but the problem is (commonly) that the EEPROM that holds the code fails when the battery voltage is low for a period of time.
Because this EEPROM is ‘tied’ to the one in the alarm and the coding changes every cycle, it doesn’t have the facility to re-sync.
Certainly on mine - which had a sync problem just alike almost all others - the relays were working fine.
Ultimately the cost of a replacement immobiliser is around �55 so is far less than the repair cost would be, even if it were possible.
There is a security benefit in fitting a replacement immobiliser in that the new one has a dedicated keytag rather than operating from the ignition key (which still works for the alarm module, btw).
Thinking about this failure mode, which is similar to mine,
The immobiliser is getting the signal to engage the relays as the pump is running but the crank signal is not being sent to the main high current relay.
I had crank today but no fuel. Car stated fine a couple of mins later. If the problem persists I will have a go at repairing the module.
[quote=tlracer]Some time ago I stripped one down to see if it could be repaired, but the problem is (commonly) that the EEPROM that holds the code fails when the battery voltage is low for a period of time.
Because this EEPROM is ‘tied’ to the one in the alarm and the coding changes every cycle, it doesn’t have the facility to re-sync.
Certainly on mine - which had a sync problem just alike almost all others - the relays were working fine.
Ultimately the cost of a replacement immobiliser is around �55 so is far less than the repair cost would be, even if it were possible.
There is a security benefit in fitting a replacement immobiliser in that the new one has a dedicated keytag rather than operating from the ignition key (which still works for the alarm module, btw). [/quote]
That’s a good comment actually, sounds like there are a few benefits to just getting a new one.
[quote=lotus_fatboyii]Thinking about this failure mode, which is similar to mine,
The immobiliser is getting the signal to engage the relays as the pump is running but the crank signal is not being sent to the main high current relay.
I had crank today but no fuel. Car stated fine a couple of mins later. If the problem persists I will have a go at repairing the module. [/quote]
If you’re getting intermittent cranking, it could be the starter motor.
I had a similar problem which definitely wasn’t immobiliser, caused by wear in the starter gear/lever assembly. This was sticking, hence the solenoid wasn’t closing and so the high current feed wasn’t getting to the starter motor.
Remedy was to take off the starter, strip & fit a new assembly (about �14 from www.woodauto.com) and all was well again!
If your fault is definitely inside the immobiliser send me a PM and I will reply with the part numbers for both relays.
mine wasnt playing ball the other night. Sometimes I was getting fuel pump, but no cranking. Then it’d crank but not start due to fuel pump not running.
