Bypassing The Immobiliser (Ignition Only)
Discussion
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I was tired of this problem myself, and as I was in the middle of a complete resto, I just drilled a small hole in the footwell that comes out right in front of the starter. Drew up a wire directly from the ign switch, through a small on/off switch/button well hidden. The immobiliser still works on the fuel pump.
SILICONEKID345HP said:
Just fit a relay in the engine bay somewhere , job done . Never had a problem since
Jools made an harness up with heat protective sleeving ,Happy days
Just adding a relay is not the full answer, if the current is still passing through the immobiliser and the relay inside the immobiliser is damaged no amount of additional relays will help.Jools made an harness up with heat protective sleeving ,Happy days
Edited by SILICONEKID345HP on Saturday 23 May 17:10
If anyone wants to bypass their immobiliser all they need do is PM me, to date I've helped over 100 Chimaera & Griffith owners do just that.
TBH it's a piece of pish and costs pennies
ChimpOnGas said:
Just adding a relay is not the full answer, if the current is still passing through the immobiliser and the relay inside the immobiliser is damaged no amount of additional relays will help.
If anyone wants to bypass their immobiliser all they need do is PM me, to date I've helped over 100 Chimaera & Griffith owners do just that.
TBH it's a piece of pish and costs pennies
Can you post with pictures the cure ..If anyone wants to bypass their immobiliser all they need do is PM me, to date I've helped over 100 Chimaera & Griffith owners do just that.
TBH it's a piece of pish and costs pennies
SILICONEKID345HP said:
ChimpOnGas said:
Just adding a relay is not the full answer, if the current is still passing through the immobiliser and the relay inside the immobiliser is damaged no amount of additional relays will help.
If anyone wants to bypass their immobiliser all they need do is PM me, to date I've helped over 100 Chimaera & Griffith owners do just that.
TBH it's a piece of pish and costs pennies
Can you post with pictures the cure ..If anyone wants to bypass their immobiliser all they need do is PM me, to date I've helped over 100 Chimaera & Griffith owners do just that.
TBH it's a piece of pish and costs pennies
SILICONEKID345HP said:
ChimpOnGas said:
No, as I expect the TVR police on here would hang me for some sort of security breach.
What about a picture the immobiliser and its location ,that would be a starting point .http://www.abacuscaralarms.co.uk/tvr-alarms.html
Simply scroll down the page a bit.
The rest doesn't take a genius, just a multimeter and a bit logic
Ok I give in, after all the information is out there on the Abacus Alarms website anyway so I'm not revealing anything that can't be found easily by anyone who chooses to search for it.
The immobiliser sits behind the head unit while the alarm unit sits under the dash top, it's important to understand they are paired together. You can not replace one without the other or at least getting the help from a Meta expert.
You can complete the bypass utilising the existing loom, but probably the simplest way to bypass the Meta system and it's failing internal relay is to leave the above two units well alone.
Simply run a new wire direct from the sprung start terminal on the ignition switch to trigger a relay, use a quality four terminal 12v 30amp fused relay mounting it somewhere dry and easily accessible but as close to the starter solenoid as possible.
Triggering the switching side of a relay (terminal 86) from the sprung start position will mean the contacts inside your ignition switch will only ever have to deal a low amp load.
For this reason the relay is essential to ensure switch longevity as it was not designed to take a lot of amps, the Vauxhall ignition switch was never the most robust at the best of times and it's probably almost 20 years old now, so don't overload it!
Take your higher amp live to directly supply the starter solenoid from the battery or thick red starter lead, connecting it to terminal 30 on your relay, then run a second wire from relay terminal 87 to the starter solenoid itself.
The starter solenoid will pull around 10-15 amps max during cranking but I would specify a wire gauge capable to taking 30 amps as there is no harm using slightly heavier gauge but you certainly don't want it too light.
Finish the job by earthing your relay from terminal 85, on a TVR by far the most reliable earth is always going to be the negative battery terminal.
You've now created a brand new starter solenoid circuit completely bypassing the Meta system with the ignition switch terminal properly protected by a relay and the whole circuit protected by a 30amp fuse.
Because the Meta system has now been bypassed what you'll find is you can crank the engine on the key without pressing your alarm fob, but because the ECU live is still passing through the Meta system you will not be able to start the car until you disengage the immobiliser.
The ECU runs the fuel pump for a few seconds to prime the fuel rail, that's the buzz you hear when you disengage the immobiliser, it will only run the fuel pump continuously when the ECU sees an RPM signal (IE cranking or engine running).
You could bypass the Meta system on the ECU circuit too, and in exactly the same way as I've explained on the starter solenoid circuit, but this is seldom needed. Should you choose complete the double bypass you will need to add back in some form of immobilisation to ensure the car is secure when left.
The best way to do this would be to add a second relay and a momentary switch to your newly created starter solenoid circuit.
This clever little 'logic' circuit works like this.....
1. Turn the ignition key to the "ignition on" position (warning lights on)
2. Press and release your hidden momentary switch
3. Turn the key to the "sprung start" position, crank & start the engine as normal
The button press momentarily energises the coil of Relay 1 which allows +12V out of terminal 87 and into terminal 86. This has the effect of keeping the coil energised after the button is released (note that whilst the button is pressed there is 0V between terminals 86 and 87).
Terminal 87 also sends power to the coil of Relay 2 which enables the starter motor solenoid connection and ready for when the key is turned to the "sprung start" position.
And now for the clever bit...
When the ignition is turned off the power to the coil of relay 1 is cut which cuts the power to the coil in Relay 2 and breaks the starter motor solenoid circuit, so the engine cannot be started again without going through the above routine.
You will never forget to immobilise the car when you leave it because with the double relay & hidden momentary switch system is always activated automatically when you switch off & remove the key.
Here's how this clever double relay immobiliser circuit looks in a schematic drawing:
Remember, you only really need this system if you have bypassed the Meta system on both the starter solenoid & ECU circuits that pass through it.
The truth is the little relay inside the the Meta unit is over specified for the very low amps drawn by the ECU so it seldom gives issues, this is because TVR used the higher amp Meta internal relay (designed for the starter solenoid)for the ECU. They then used the lower amp rated internal relay for the much more demanding starter solenoid circuit, basically they got their wiring back to front
This is why it fails!!!
The very common "Hot Start" issue is actually a bit misleading, it should really be called the "Meta internal relay failure = no start" issue. The only reason the problem first raises it's ugly head when the car is hot is because resistance in any electrical circuit increases dramatically with a rise in temperature.
Eventually the relay will fail completely irrespective of temperature, at which point you'll have a "cold start" issue too
Sadly it's no good just switching the circuits around so you're using the correctly rated internal Meta relays as the damage to the low amp relay will already have taken place.
For this very same reason you can not permanently fix the "Hot Start" issue with the hot start kit, you may temporarily elevate the symptoms but because the feed to the starter solenoid is still being passed through the damaged Meta low amp internal relay the problem is sure to return.
And Sodd's law dictates it'll be certain to happen one dark and rainy night miles from home!
The only permanent fix for what is known as the "Hot Start" issue is to complete the above bypass, or better still have the Meta system (with it's damaged internal relay) replaced by someone who understands what they're doing.
My advice is.. Don't rely on the hot start kit to solve the problem, at best it'll mask the real issue and at worst it'll fool you into thinking you've fixed the problem only for you to find you've broken down in the middle of nowhere with no easy way of getting out of trouble.
You have been warned!
The immobiliser sits behind the head unit while the alarm unit sits under the dash top, it's important to understand they are paired together. You can not replace one without the other or at least getting the help from a Meta expert.
You can complete the bypass utilising the existing loom, but probably the simplest way to bypass the Meta system and it's failing internal relay is to leave the above two units well alone.
Simply run a new wire direct from the sprung start terminal on the ignition switch to trigger a relay, use a quality four terminal 12v 30amp fused relay mounting it somewhere dry and easily accessible but as close to the starter solenoid as possible.
Triggering the switching side of a relay (terminal 86) from the sprung start position will mean the contacts inside your ignition switch will only ever have to deal a low amp load.
For this reason the relay is essential to ensure switch longevity as it was not designed to take a lot of amps, the Vauxhall ignition switch was never the most robust at the best of times and it's probably almost 20 years old now, so don't overload it!
Take your higher amp live to directly supply the starter solenoid from the battery or thick red starter lead, connecting it to terminal 30 on your relay, then run a second wire from relay terminal 87 to the starter solenoid itself.
The starter solenoid will pull around 10-15 amps max during cranking but I would specify a wire gauge capable to taking 30 amps as there is no harm using slightly heavier gauge but you certainly don't want it too light.
Finish the job by earthing your relay from terminal 85, on a TVR by far the most reliable earth is always going to be the negative battery terminal
.You've now created a brand new starter solenoid circuit completely bypassing the Meta system with the ignition switch terminal properly protected by a relay and the whole circuit protected by a 30amp fuse.
Because the Meta system has now been bypassed what you'll find is you can crank the engine on the key without pressing your alarm fob, but because the ECU live is still passing through the Meta system you will not be able to start the car until you disengage the immobiliser.
The ECU runs the fuel pump for a few seconds to prime the fuel rail, that's the buzz you hear when you disengage the immobiliser, it will only run the fuel pump continuously when the ECU sees an RPM signal (IE cranking or engine running).
You could bypass the Meta system on the ECU circuit too, and in exactly the same way as I've explained on the starter solenoid circuit, but this is seldom needed. Should you choose complete the double bypass you will need to add back in some form of immobilisation to ensure the car is secure when left.
The best way to do this would be to add a second relay and a momentary switch to your newly created starter solenoid circuit.
This clever little 'logic' circuit works like this.....
1. Turn the ignition key to the "ignition on" position (warning lights on)
2. Press and release your hidden momentary switch
3. Turn the key to the "sprung start" position, crank & start the engine as normal
The button press momentarily energises the coil of Relay 1 which allows +12V out of terminal 87 and into terminal 86. This has the effect of keeping the coil energised after the button is released (note that whilst the button is pressed there is 0V between terminals 86 and 87).
Terminal 87 also sends power to the coil of Relay 2 which enables the starter motor solenoid connection and ready for when the key is turned to the "sprung start" position.
And now for the clever bit...
When the ignition is turned off the power to the coil of relay 1 is cut which cuts the power to the coil in Relay 2 and breaks the starter motor solenoid circuit, so the engine cannot be started again without going through the above routine.
You will never forget to immobilise the car when you leave it because with the double relay & hidden momentary switch system is always activated automatically when you switch off & remove the key.
Here's how this clever double relay immobiliser circuit looks in a schematic drawing:
Remember, you only really need this system if you have bypassed the Meta system on both the starter solenoid & ECU circuits that pass through it.
The truth is the little relay inside the the Meta unit is over specified for the very low amps drawn by the ECU so it seldom gives issues, this is because TVR used the higher amp Meta internal relay (designed for the starter solenoid)for the ECU. They then used the lower amp rated internal relay for the much more demanding starter solenoid circuit, basically they got their wiring back to front
This is why it fails!!!
The very common "Hot Start" issue is actually a bit misleading, it should really be called the "Meta internal relay failure = no start" issue. The only reason the problem first raises it's ugly head when the car is hot is because resistance in any electrical circuit increases dramatically with a rise in temperature.
Eventually the relay will fail completely irrespective of temperature, at which point you'll have a "cold start" issue too
Sadly it's no good just switching the circuits around so you're using the correctly rated internal Meta relays as the damage to the low amp relay will already have taken place.
For this very same reason you can not permanently fix the "Hot Start" issue with the hot start kit, you may temporarily elevate the symptoms but because the feed to the starter solenoid is still being passed through the damaged Meta low amp internal relay the problem is sure to return.
And Sodd's law dictates it'll be certain to happen one dark and rainy night miles from home!
The only permanent fix for what is known as the "Hot Start" issue is to complete the above bypass, or better still have the Meta system (with it's damaged internal relay) replaced by someone who understands what they're doing.
My advice is.. Don't rely on the hot start kit to solve the problem, at best it'll mask the real issue and at worst it'll fool you into thinking you've fixed the problem only for you to find you've broken down in the middle of nowhere with no easy way of getting out of trouble.
You have been warned!
Hi gents, any chance someone could pm me the immobiliser bypass? Car was left out whilst my garage was being built in the winter and now wont start. Starter motor cranks, but no fuel pump wine, fuel pump does go though with a 12v direct feed. Tried 2 new relays for FP and ECU to no avail. FP relay is getting permanent 12v live (pin 30) but nothing out of the switched live when cranking the engine. Many thanks - Lee
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