Wiring diagram - 2 litre Mark 3

Technical Area Engine, Transmission, Exhaust etc
2

 

Hello folks

I have a problem with my import Mark 3 MX5. I desperately need a full wiring diagram - can anyone help?

About six weeks ago my car would not start. I thought it was the battery so charged it overnight and it still wouldn't start. The RAC came and took it to my local Mazda dealer. They couldn't get their diagnostics machine to talk to my car and said it was because it was a grey import.

My local garage (non Mazda) has now taken up the challenge. They disabled the thatcham imboliser and managed to talk to the dash, airbags etc. But they couldn't get a can reading from the ECU. They sent the ECU off to a firm in Essex to see if it was that but they couldn't replicate the fault. Having tried to fit 2 second hand ECU's we are still not able to start the car. It appears to be that imobiliser such won't turn off to start. We think it could be an electrical problem - but trying to get a wiring diagram for the whole car is proving very difficult.

Any help that you can offer would be very much appreciated.

Many thanks
Ellie
3

Hi Ellie

Got your message, and had word with RR, who doesn’t think he has anything for an import. Did you email him as well just in case ?

4

 Thanks Martin. I do think that UK spec diagrams will also help.

Cheers

Ellie

5

 

Hi Ellie -

I’ve just highlighted that word above in red (can) AFAIK there’s no ‘can bus’ on a MK3, but there should be an OBD socket in the fusebox under the dash - if it’s the same place as a Mk2.5? ‘Can bus’ is used by Ford, but not by Mazda. If they are trying to read from the diagnostic socket under the bonnet then they can’t read engine diagnostics, they have to use the OBD one.

Best regards btw!

6

Ellie,

I don’t know if this will help but you can try looking here:

http://www.mellens.net/mazda/index.html

Look in item 7 [2006-2007 Miata Service Manual] - last entry [No58] is for wiring - I don’t know ow comprehensive it is, but some of the other pages may help you.

John

7

If the immobiliser has been disabled why do they still think it’s causing a problem?

Gerry, NC does have a HS-CAN. There is no under the bonnet DIAGNOSTIC plug like on NA and NB, only the 16 pin DLC under the dash.

8

 Ooops - thanks Robbie - first time I heard that. Sorry Ellie.

Robbie - what’s the default on the immobiliser, does it default on or off?

9

Depends what immobiliser it’s got. For an OE one, the default is engine won’t start unless the instrument cluster sees a registered key and sends a signal to the PCM to allow the engine to run. I think Ellie’s car must have had an aftermarket immobilser fitted.