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Discussion Starter · #1 ·
Hi, I have a year 2000 mk2 showing fault code/s. I'm using this site that lists the codes, assuming the info is accurate:


I have a video of the codes here:


Wondering what you guys work the codes out to be?

Thanks..... 馃榾
 

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My first impression is P0115 which a quick google suggests is coolant temperature sensor signal out of range.

PS I didn't check your link first. It explains how to read OBDI codes from a Mk.1 but not OBDII codes from later cars. Those are 4-digit codes where each digit is a long flash followed by a number of short flashes. You count the short flashes. So your video seems to show zero, one, one, five then that's repeated.
 

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Discussion Starter · #3 ·
My first impression is P0115 which a quick google suggests is coolant temperature sensor signal out of range.

PS I didn't check your link first. It explains how to read OBDI codes from a Mk.1 but not OBDII codes from later cars. Those are 4-digit codes where each digit is a long flash followed by a number of short flashes. You count the short flashes. So your video seems to show zero, one, one, five then that's repeated.
Thanks 馃憤馃憤馃憤
Yes, I agree.. After further reading, it seems your right and I have a 4 digit code being shown. My car supposedly is obd1? - at liest I thought so, but I'm wondering if it has a obd1 diagnostics port, but actually runs the obd2 system? As I first thought it was showing codes 11,11,15. But why 11 twice, and there is no number 11 fault code!
But then after more searching I figured 115 was the corect code, which would be p0115 - and like you say, coolent temp sensor. - which I just happened to change at the weekend fault finding another problem! It was bought from mx5 parts. - everything from them seems to be junk in my experience. Oem all the way from now on. (I checked the codes due to noticing poor mpg over the last week.)

My original problem is a hesitation/boggyness on a cold engine in the morning until about 3k RPM when it picks up. Once engine is warm, it's fine. Also, when car is warm, switch off engine, start up again, and after 10 seconds roughly, I get a drop in revs, then back up to idle and everything's fine. Only happens once, and only on a warm/hot engine, and sometimes its not too noticeable, sometimes more so.

The car is pretty much ready for turbo conversion now, but can't go any further until I fix this. In turbo prep, and fault finding this minor issue I have already replaced various parts. These being: coil packs (supposedly decent ones made by autolink - seem good), ngk plugs, Jr ht leads, air filter, lambda sensor (aftermarket from mx5 doctor on abay - maybe a bad idea, but noticed no difference upon replacement). Exhaust is custom made, with new magnaflow metallic cat. Cleaned the Maf with Maf cleaner. Thought I would try the temp sensor, but seem to have made things worse. Maybe replaced an already failing one with an even worse one?
Any suggestions very welcome thanks...
 

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Mazda introduced OBDII codes before they began fitting the cars with OBDII ports. Late Mk.1s have 4-digit codes too. Miatas got the OBDII ports first, presumably due to regulatory requirements there. Rest of the world followed suit a few years later.

Not sure what your issue is but coolant temp sensor is a possibility. Ironically if you already had a turbo conversion with an aftermarket ECU you could just plug in a laptop and read the sensors directly.
 

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Discussion Starter · #5 ·
Mazda introduced OBDII codes before they began fitting the cars with OBDII ports. Late Mk.1s have 4-digit codes too. Miatas got the OBDII ports first, presumably due to regulatory requirements there. Rest of the world followed suit a few years later.

Not sure what your issue is but coolant temp sensor is a possibility. Ironically if you already had a turbo conversion with an aftermarket ECU you could just plug in a laptop and read the sensors directly.
Thanks.. But yes, I have a megasquirt ms3 mini sitting here! , but not plugged it in yet, as typically I don't have a laptop to connect it too,,, yet!.. 馃檮
 

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Interesting im gonna run the codes on my 99 when it stops raining...i have same fault on warm up.. part throttle crap running bogs down.perfectly fine when warm. I recently changed the Ect sensor on back of engine and still no good. The original sensor had scale onit and i thought at the time possibly insulated the true temp reading...my replacement was from mx5parts...and not solved problem.. test not guess ill run the diag.

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Discussion Starter · #7 ·
Interesting im gonna run the codes on my 99 when it stops raining...i have same fault on warm up.. part throttle crap running bogs down.perfectly fine when warm. I recently changed the Ect sensor on back of engine and still no good. The original sensor had scale onit and i thought at the time possibly insulated the true temp reading...my replacement was from mx5parts...and not solved problem.. test not guess ill run the diag.

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Hi, sounds similar.. You don't get the rev drop for a couple of seconds after starting when engine hot and waiting about 10 seconds? Its like the ecu switches off the choke (im oldskool lol) after detecting the engines warm, or switches between open and closed loop or something, but this causes a drop in revs, which it doesn't normally do.
I've put my old ect sensor back in and my mpg is all good again now, but still had the rev drop thing when hot, and I expect it will be a bit boggy still in the morning when cold tomorrow.
I will check for codes again, but I didn't ever have any showing until I put in the new ect sensor. So I'm not expecting any more to show now. Annoyingly.
I'm going to order a genuine ect sensor anyway incase my good one is not actually so good.
 

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No once its warm its fine. Cold til half warm fine then throttle doesnt work change down higher revs fine . About 2 mins real rough then fine allday once warm..it doesnt allways doit cold either.
When it stops raining ill do a code read and resitance check off oem and mx5parts ect. Im tempted to put old oem back in now ive descaled it.
Another thing to mention ive got the long reach sparkplugs fitted ( sit lower better perf/ mpg apparently). I was gonna try original. Done maf clean etc.

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Discussion Starter · #9 ·
No once its warm its fine. Cold til half warm fine then throttle doesnt work change down higher revs fine . About 2 mins real rough then fine allday once warm..it doesnt allways doit cold either.
When it stops raining ill do a code read and resitance check off oem and mx5parts ect. Im tempted to put old oem back in now ive descaled it.
Another thing to mention ive got the long reach sparkplugs fitted ( sit lower better perf/ mpg apparently). I was gonna try original. Done maf clean etc.

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I did put in some new ngk's recently, got off ebay. They were the cheapest seller. Another bad idea probably, my father said he tried a bunch of ngk's in his saab, none of them were any good, until he fitted champions. Apparently there are plenty of fakes out there. I better have a look at mine and maybe get some from a reputable dealer. 馃
 

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Discussion Starter · #10 ·
Also, possible coolent leak into a cylinder when sitting overnight, then burnt off In morning? Hopefully not though! 馃槵
 

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Yeah... mine got hot at a track day lol this year.. but level is spot on so were not that worried lol

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Discussion Starter · #13 ·
Also would be instant misfire not part warm that mine is.. its like throttle dead on mine.

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馃憤馃憤
Let me know if you get any codes, and if you manage to suss out the issue 馃榿馃憤馃憤
 

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Ok so my 99 diag box has no markings atall...so wheres fen on a mk2?


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Discussion Starter · #17 ·
Nothing on here. Mk1 way dont work.


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That's weird, I never found that info that you have above.. I just used the video in this link:

My diag box also is blank, but it seemed to work OK as you can see in the video I posted.
 

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Discussion Starter · #18 ·
Also, the led that you use needs a resistor in it to work, depending on what coulor the led is.. My led already had the resistor in the back (got it from work)..
 
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