Long story - My engine light came on, my local garage said they thought I needed a new battery, I went away, when I returned the car wouldn’t start, so assumed it was the battery, changed the battery and all seemed ok. Then a few days later the engine light came back on, took it back to the garage and they couldn’t find a problem, went to pick it up and it wouldn’t start, basically I put the key in the ignition and the red key light wasn’t coming on, so when you tried to start it nothing would happen. Garage kept it thought they had solved it, they took stearing column off cleaned up all the connections etc. However once I got it home, i used the car a few times and it was fine, then next time it wouldn’t recognise the key again, this time the engine turned over but wouldn’t spark. My local garage thought it might be the immobiliser, and thought I might just need to get it recoded with the keys which he couldn’t do. So took the car to Northampton Mazda, they were going to do a diagnostic, when they contacted me they couldn’t do a diagnostic as they didn’t have the right one, theres had been stolen, and they told me on experience they thought I needed a new immobiliser, I wasn’t happy that they hadn’t done a diagnostic, so towed the car to Coventry Mazda who informed me they had the right diagnostic kit (believe it was vrm 1), anyway they came back to me said they had done a vrm 2 diagnostic and that the code p1602 showed and I needed a new pcm to get the dash working and it would cost me just under £2,000. I can’t see how it can be the dash as all the other lights on the dash are working. My local guy told me that you can send pcm’s away for testing and repair and said he could do this, but he doesn’t think this is the problem but it was a starting point, so brought the car back, he has checked with the repair firm and unfortunately they now say they would need the whole car to test the pcm, and they are a long way away from where I am. I am now totally confused, I would just like to get the car back on the road (been without it for around 6 weeks now), I don’t want to get the pcm replaced and then get told I now need an immobiliser. Now the car will not recognise any of the keys at all, but if you press the fob then the red light comes on, on the dash. If anyone has got any ideas, or can suggest somewhere that I can take the car it would be greatly appreciated. The car is a 2005 MX5 1.8 icon.
I too would be suggesting immobiliser.2k is mad money. We have perfect used kits (3 pieces as “married set” and do not mix n match)All 3 items need to be fitted at same time .I have known immobilisers to react like yours where sometimes it starts sometime
s it does but was informed by Mazda dealer years back that you can get up to maybe 10 starts before unit shuts down fully
Just had a very similar problem with a Mk2.5, crank angle sensor changed - problem solved. hope may help, our first thoughts were injector relay but that was ok, had big spark, no fuel going through, and all indications ok, key fob worked as should etc, immobiliser, dash lights etc, no codes showing. Paul H.
Long shot, I had similar problems with my MK2.5
Try re programming the keyless entry system as explained in the post below.
It sorted mine.
You never know your luck.
http://www.mx5oc.co.uk/forum/yaf_postst95836_NB-Central-Locking-not-functioning.aspx
(Sorry can’t link the above, tablet won’t let me. You will have to copy and paste)
Here’s the instructions:
Registering Keyless Entry Transmitters NB & NC
- Shut all doors and remove key from the ignition switch
- Open drivers side door
- Insert key into ignition, switch ignition on, then off then remove key 3 times.
- Close then open drivers door 3 times (all doors should lock then unlock)
- Press unlock button twice on the transmitter (doors lock then unlock to confirm)
- Press unlock button twice on all other transmitters to be registered to the car (doors should lock and unlock to conform each transmitter registered)
- Switch ignition on to cancel set-up mode.