Fault code diagnosis

[leamyj]

Dunno if everyone is aware of how to diagnose your fault codes, here's a handy guide

http://www.mx5oc.co.uk/forum/forums/t/204.aspx

My mk2 has the same diagnostic set up as the mk1, obd2 didn't arrive on to the mx5 until the mk2.5

I accept no responsibility for the content of this guide.

John

PS.. also here

http://www.mx5parts.co.uk/product_info. ... ucts_id/35

[franksm]

This only works for cars up to 1995

After 1995, OBD2 was introduced. You can get the LED to flash codes, but they won't make sense unless you have an OBD2 reader. For cars up to 1995, the codes read fine with the LED and it's a useful trick

[leamyj]

Frank, Can you tell me whether my '99 mk2 is using obd2 or not?? The diagnostics box is located in the engine bay in the same location as the mk1 and is configured same as the mk1..no obd2 interface that I can see..or is there an adaptor that one can get??

Other forums/websites state that the mx5 didn't get obd2 until the mk2.5, which was around 2002???

john

[franksm]

Yeah, yours will be obd2

You can get a generic reader quite cheap, but will need to make up an interface for the Mazda-specific socket - or else buy one that has an adaptor (not so cheap).

I think Diurmuid bought one so might be able to say what's what.

If you want an interface for a laptop, the ELM 327 is the best - laptop versions are great as they will graph information easily. Still, the ELM comes with a standard interface so you'd still need to hunt out a Mazda socket for it

[charged_rs]

mk2 jap imports dont use obd2

they use the same diagnostics as a mk1

it was only the jap import mk2.5 that used obd2 and the connector for these is near your bonnet release cable.

[franksm]

I don't get it... does that mean that Japanese imports have different ECUs to rest-of-world cars ? That LED code-reader on my Irish '96 didn't work due to the OBD2 thing.

These are the articles I am going by:

http://www.miata.net/garage/Engine_Diagnostics.html
"Note that this may not work for models newer than 1995 (OBD-II)"


http://www.miata.net/garage/obdii.html
"Mazda Specific OBDII Trouble Codes"
"These codes are as of 12/04, so they should apply to all '96 -'05 Mazdas. Trouble codes less than 1000 are generic OBDII codes and apply to all OBDII compliant vehicles as a minimum Federal Standard. It should be noted that in '08 all manufacturers will be required to move to the CAN protocol, and movement has already started in that direction. For example, the Mazda 6 and RX-8 are already using CAN. This means that scanners previously used for OBDII likely will not work in these vehicles."


http://www.miata.net/garage/faultcodes.html
"Note that the following codes are for '93 and older models. Beginning in '96, the Miata used OBD (On-board diagnostics) which requires a special scanner to read the codes"

[leamyj]

Now I'm REALLY confused

[Steve]

This only works for cars up to 1995

I thought so too, is this not the case?

Heres a post on it :
"Wherever I have searched it is suggested that the Eunos Roadsters were never OBD-II compliant, they only have the darn DIAGNOSIS connector in the engine bay for troubleshooting the engine fault codes."
http://forum.miata.net/vb/showpost.php? ... ostcount=3

Heres a guide to the connectors :
http://codes.rennacs.com/Petrol-Engine/ ... ngines.php

another good guide on reading codes for (early)Mk1's :
http://web.archive.org/web/200804150938 ... agnostics/

[charged_rs]

all the mk2 imports i have had , even the mk1 imports have never been obd2 compliant

its a uk / european thing...

[Steve]

all the mk2 imports i have had , even the mk1 imports have never been obd2 compliant

its a uk / european thing...

ahh... as in JOBD/EOBD?