From 1996 till 2002 TVR vehicles were fitted with the Meta M99 alarm & M36 immobiliser systems, both systms conform to Thatcham Cat1 status (insurance approval). These are extremely reliable systems, alarms fitted in the late nineties are still working perfectly today. There are two versions of the M99/M36 combination, the M36/M99 system were fitted up to mid 1999, after 1999 the M99T2/M36T2 were fitted. 

Technical Information:

The Meta M36T & M36T2 are Thatcham Cat 2 approved immobilisers, the earlier M36T unit interrupts three circuits, the later M36T2 interupts 2 circuits so rendering the vehicle immobile. The starter motor and the fuel pump circuits are cut and by-passed through the M36T2, once a valid Meta touchkey (model number RK36s) is inserted into the socket the M36 disarms allowing the vehicle to be started. If the vehicle is not started or the ignition not switched on within 15 seconds the immobiliser will re-arm. The M36T2 comes pre-programmed with two RK36S touchkeys, a total of 5 keys can be coded in, once this limit is reached further keys cannot be coded & the immobiliser will need to be removed or replaced. If the M36 has been paired with a M99T2 alarm (see below) this also uses up one memory space on the M36.

A new M36 only has space for three extra touchkeys. If the M36 is paired with a M99 alarm system another position is used up. Once a RK36s is coded into an immobiliser the same key cannot be coded to another immobiliser, do not purchase second hand or previously used touchkeys - they will not work. To code in a new RK36S a working RK36S is required, without which it is not possible and the immobiliser will have to be replaced or removed.

The M36T2 fitted to many TVR vehicles is paired to a M99 alarm system as standard. The connection between the two is via a digital link, as the M99 has only one memory space it can only be paired once to a M36. The M36 can be paired to another M99T2 providing a working touchkey is available and a memory space is free. There is no way to determine how many spaces are free or used up.

Common Problems:

Remote Fobs:

Fob fails to operate alarm - replace batteries and/or re-sync fob to alarm. Please note this proceedure will only work with fobs pre-coded with the 16 digit code.

Fob syncing proceedure

  1. With a working fob arm and disarm the alarm sixteen times or until the alarm stops responding, alarm now in program mode.
  2. Once in program mode press the button of the new remotes(s), press the button of the original remote(s). This must be done within 8 seconds of each action. If 8 seconds pass without any actions the alarm will automatically exit programming mode and you will have to start from step 1.
  3. Wait 8 seconds to exit learning mode.
  4. Test remotes.

Replacement fobs & cases: 

Type of TVR supplied fobs

Replacement fob cases can be purchased here: Fob Cases

Replacement fobs can be found here

To program a new fob to the M99 brain you need the code card with a 16 digit hexadecimal code number and a working fob, the 16 digit code needs to be pre-programmed to the remote (by a Meta dealer). Without either code & 16 digit code it will not be possible to code a new fob. 

The M99 can be re-coded with two fobs & 16 digit number, call 0208 677 1999 or click here for more info. 

To code a new RK36s touchkey to a M36 a working touchkey is required without which it will not be possible to do.

Siren problems:

Siren sounding when indicator lights are not flashing - replace siren

The siren is probably the most problematic part of the alarm system, when this goes wrong it can cause some odd alarm conditions, such as going off when arming/disarming or sounding for a few seconds while driving the car. If the siren sounds for no reason (usually the indicators do not flash) e.g. while driving the car and does no respond to the remote fobs is usually an indication the unit is faulty and needs replacing. The siren for the M99T model (M11A) is no longer available however we can now supply a replacement which needs a simple modification to the alarm - more info

For the earlier M99 systems water can penetrate the M11a siren a cause a short circuit, in extreme circumstances this can cause the M99 conrol box to burn out, usually a repair will not be possible & the M99 will need to be replaced.

M99T2 fitted sirens are still available (SC1T2) and can be purchased here. The SC1T2 can also short out the alarm, this can usually be repaired, call 0208 677 1999 for more info

Please note both the above sirens are digitally controlled and an aftermarket 12 Volt siren will not work with the existing wiring.

Alarm disarms but car will not start:

If the battery has been disconnected for long periods of time can cause the immobiliser to fail, usually indicated by the LED found on the touchkey receptacle not flashing, if the immobilser fails to recognise the touchkey this is a sign the immobiliser has failed.

Immobiliser does not disarm using the touchkey

Check the contact pins within the socket are present, on old sockets these can break off. Replacement M36 sockets available here


The car fails to start when the engine is hot (TVR's)

The M36 immobiliser:

The M36T2 immobiliser is a two circuit Thatcham approved immobiliser, it is manufactured with very high quality components to a very high standard & as such this is one of the most reliable immobilisers manufactured today, many of these systems are still working perfectly on vehicles which are well over 15 years age.
Problems arise because TVR have wired the immobiliser circuits the wrong way around. The M36 has two immobiliser circuits, circuit 1 can handle currents of up to 10 Amps & should be wired to the fuel pump or ignition circuit, circuit 2 is rated at 25 Amps & is designed to be connected to the starter motor circuit. TVR have wired these circuits the wrong way round, the starter goes through the 10 amp while the fuel/ignition goes through the 25 amp circuit. All being well there are no problems even though the two relays are wired the wrong way around. Problems arise when the starter solenoid begins to wear, in so doing it demands more & more power to function, when the current flow to the starter gets passed the 10 Amp limit of circuit 1 problems start. This situation gets worse when when the engine is hot which in turn makes the starter solenoid hot causing it to demand more power. This is known as the hot start problem, eventually the starter circuit will burn out causing total failure of the starter. Adding an extra 'hot start' relay to this circuit is not a permanent fix as the starter will still demand more power which could eventually burn out the ignition switch or associated wiring leading to the failure of the starter itself. Before this happens we recommend to have the starter inspected & have it repaired or replaced if found faulty.

All replacement TVR adapted M36T2 immobilisers will now be sent out with the immobiliser circuits switched to match the TVR wiring, this will now match the higher rated relay to the starter circuit of the TVR, this should cut down on the hot start issue

Alarm disarms but car will not start:

If the battery has been disconnected for long periods of time can cause the immobiliser to fail, usually indicated by the LED found on the touchkey receptacle not flashing, if the immobilser fails to recognise the touchkey this is a sign the immobiliser has failed.

Alarm Locations:

Chimera; the alarm is usually located on the nearside under the dash cover, the M36 immobiliser can be found behind the stereo (photo above) - A guide of how to remove the dash cover can be found here

Cerbera; the alarm & immobiliser units are mounted behind the compartment which is found behind the rear seats.

Griffith; the alarm is usually located behind/around the glovebox area.

Tuscan; the alarm can be found in the drivers kick panel behind the pedal cluster (photo below).

Tuscan alarm location

We can reprogram both M99 versions with two TVR type remotes and a new codecard, the cost starts from £110 inclusive of next day return delivery, Click here for more info. The alarm can also be re-coded with the basic round type fobs, this & other options can be viewed here 

Complete plug & play replacement M99 & M36 system - more info

For any other information call 0208 677 1999

Send the alarm brain to:

Abacus Car Alarms
206 Leigham Court Road
SW16 2RB

Don't forget to include your details including your phone number.

Once coded with two new fobs the alarm will be checked on our test bench, once the alarm is tested ok we will contact you for payment. If paying by cheque there will be a minimum delay of six days for it to clear before unit is sent back to you.

For a fast turnaround please send via next day Special Delivery (a re-programed alarm by us is usually returned within 2 working days - weekends will take longer)

Buy Online

Complete Plug & Play Replacement M99/M36 system

If you want to keep the full functionality of the alarm system for your TVR we can now supply a complete replacement M99 alarm ECU (or the later M99T2) & M36T2 immobiliser pre-programmed self fit kit, complete with two M300 (TVR style) remote fobs, codecard & two STK1 (immobiliser touchkeys). This kit is supplied on an exchange basis for the M99 alarm, the old M36 cannot be repaired & has no value (please discard responsibly). Both the M99 & M36 are a plug & play fitment (instructions supplied). This is a direct replacement and keeps the originality of the TVR (the only difference is the TVR logo is missing from the button of the M300 fob)

M99T/M36T Replacment kit Buy Online

M99T2/M36T2 Replacment kit Buy Online

Plug & Play Replacement For The M99T2/M36T2

With Optional Remote Boot Release

Plug & play replacement alarm kit for the TVR range of vehicles fitted with the M99T2, complete with a remote boot release option for the Cerbera & Griffith. At last, open the boot without having to get into the car switch on the ignition & press the release button to open the boot, this all can be done with a single press of the remote fob, extra wiring required & simple instructions supplied. Simple plug & play swap over of the M99T2 alarm with the replacement HPA unit & plug & play swap over of the M36T2 immobiliser. This kit consists of the Thatcham approved HPAT alarm ECU & M36T2 immobiliser both fitted with suitable connections for an easy plug & play swap over. Availble for both the M99 & M99T2 systems.

Buy Online - More Information

Replacement M99 Sirens

M11a replacement  siren for the  M99t

Replacement SC1 siren for the M99T2 only


Add boot remote boot release to Meta equipped TVR's

This kit allows a three button fob to control the alarm & locking plus the addition of boot release all on one keyfob. Simple three wire fitting.

For orders outside the UK please contact the office for shipping charges, when sending from outside the EU do not mark the package value as more than $15 as UK customs will charge import duty which is non refundable & please mark the package as 'Item for repair'

Other Vehicles Fitted With Meta Systems

Alfa GTV - Fiat Coupe - Vauxhall VX220 - Lotus Else - TVR Maserati-Gt - Ferrari F430