I have a Mk 1 Harvard Edition (1997), and the immobiliser is a Dallas Key (like a small button battery) which has to be touched on a circular pad on the steering column to disarm the immobiliser. The red light on the dashboard then changes from a slow flash to a constant light, and I am able to start the car with the simple key. I don’t have an alarm or central locking.
As only one of the Dallas keys that came with the car is working, I bought a new one on ebay with a view to "programming"to give a spare key. I followed the routine suggested by Garside on a 2023 post, but with no immediate luck.
However, while trying to find a solution I have somehow arrived at a situation where the red light is flashing (quicker than previously) and I can start the car with the simple key at any time ( no need to touch the pad with a Dallas key) So at the moment the immobiliser seems to be permanently disarmed! And even when the car is running the red light continues to flash quickly. I have disconnected the battery and left for a few hours but that did not clear the current setting.
What do I do - just leave it as is, not knowing how I arrived at that point, and with the risk that it could change back to an armed system at any time? Or do I use the Dallas keys to try and clear the present programmme and start again?
Any thoughts would be appreciated.
I’m surprised that your 1997 Harvard hasn’t got a factory transponder type immobiliser, these were added from September 1995 production, VIN serial number (last six digits of the VIN) 300001 or higher. Are you sure that the touch key immobiliser has not been added and it’s not a Mazda fitted system? It sounds like you’ve put it into Service Mode, although the Mazda touch key type immobilisers flash the LED in orange in service mode and beep every half a second.
If this is the case, to exit service mode (assuming a Mazda system):
Switch the ignition off
Hold the touch key against the dashboard mounted receptacle for 7 seconds
The immobiliser buzzer sounds with a continuous tome
After 7 seconds the buzzer changes to a slower intermittent tone every half a second indicating exit from service mode
Remove the touch key from the receptacle
To program new touch keys (assuming a Mazda system):
Touch original key against receptacle and hold until it beeps and the LED turns green
Touch new key on receptacle and hold until it beeps and the LED turns green
Also, just to confirm, the VIN is 17 digits and it starts with JMZNA18P200>
Hi Robbie
Thank you for your reply to my post. Much appreciated.
The last 6 numbers of the VIN are 316***, so it would appear to be factory fitted . I have removed a panel below the steering wheel and the wiring to the immobiliser does seem to be integrated with the general wiring ( which I assume might indicate factory fitted ?)
At the same time I located the immobiliser which is a Temic 3x0980 .
Do your recommendations to exit service mode and programme new touch keys still apply to the Temic immobiliser system?
Just to say, you and other posters mention the system buzzing or beeping - my system is totally silent, apart from a faint click when the system is re-armed. The light is also red, not orange/green as you mention. At the moment it is flashing with 2 rapid flashes, then a longer gap.
Out of interest, what does the service mode do? And can you tell me how I managed to get into service mode - as I said previously, I happened upon it when I was trying to programme the new key.
For your information I have attached a couple of pics showing the “pad ” on the left and the indicator light to the right, and the touch key that originally came with the car.
Thanks again for your help
That doesn’t look like an OE touch key immobiliser system. The touch key and LED are mounted in different positions on your car to where they would be on the OE system.
The last 6 of your VIN, the photo of your ignition switch and the presence of the Timec immobiliser unit confirm that you car is a later one and would have been fitted with a transponder type immobiliser from the factory where the black part around the ignition switch is an antenna which picks up a code from a chip in the ignition key and the immobiliser unit checks the code and allows the engine to start (in simple terms). You should have an immobiliser light on the instrument cluster that comes on when you start the engine then turns off once it’s running.
Your touch key system seems to have been added for some reason at some point and unless it’s the same system as Mazda fitted I’m not going to be able to offer much more advice regarding it to be honest. Service mode is basically to prevent someone who is working on the car, for example having to use the touch key each time they want to start the engine.
For a Mazda touch key system, putting the system into service mode is the same as taking it out.
Thanks for your helpful comments. When I bought the car (used), I assumed this was a standard set-up…
Just below the indicator light there is what looks like a sort of socket - see pic below. There is a cable running from that socket which has been cut off behind the dashboard. Do you know what this socket is, and would it have anything to do with the immobiliser set up?
I also attach a pic of my key. Is this a transponder type of key?
Can I just continue to use the car in service mode (and effectively ignore the immobiliser?) Bearing in mind the light flashes continuously, even when the engine is running - would this be a drain on the battery?
I don’t recognise the socket in the 1st photo, but it looks to be in the position that a Mazda fitted touch key receptacle would have been. Above your right knee?
The key is a transponder type key.
If it were mine and the Immobiliser light on the instrument cluster indicates that the factory system is working, I’d remove any aftermarket add on stuff which it seems that you have.
Thanks, for your help
If I come out of service mode. and then later want to get back into it again, how do I do that?
Thank you.
I’m still trying to work out why the previous owner would have put in a touch button system in addition to the factory installed transponder key system. Thought it provided extra security against theft perhaps??
Hi Robbie and Malc
You obviously have a lot of knowledge about the MX5 Mk 1. I am trying to understand out how the additional “touch button system” might have been wired into the car, which obviously had a Temic transponder system already installed at factory. Have you any thoughts on how this might have been achieved?
My knowledge of the Mk1 is limited to knowing that the pop-up headlamp motors do not reverse so consequently they are not to be messed about with. They are powerful enough to do a lot of damage to your fingers.
I was only helping out by quoting from an earlier reply that you had not seen.
As far as the additional alarm is concerned all I can suggest is that you start to trace all the wires and see where they go. Sometimes they do not use all the wires but still route them into the loom.