Broken Mk1 Mx5 PCM signal - help required please!

[Munter]

franv8 said:

This has gone into p*** poor fault finding mode on the part of the Mazda garage. They're changing parts without diagnosing the problem properly, and will go on changing parts until either

a) you have a 100% new car

or

b) it starts working again.

Bearing in mind the original fault was blowing fuses, was there any conclusion on the root cause of that?

It looks that way.

But they are the 2nd person to suggest it, and for all we know at the other end of a keyboard they might have run some tests against the ECU and found it was the fault.....possibly. I mean they have had enough time.

My suggestion would be a 1.8 ECU for as little as you can spend on it from a scrapy or parts supplier. If it doesn't fix it flog teh ECU on e-bay....

[spikeyhead]

There are a few being broken on ebay.

[ali_kat]

Munter said:

franv8 said:

This has gone into p*** poor fault finding mode on the part of the Mazda garage. They're changing parts without diagnosing the problem properly, and will go on changing parts until either

a) you have a 100% new car

or

b) it starts working again.

Bearing in mind the original fault was blowing fuses, was there any conclusion on the root cause of that?

It looks that way.

But they are the 2nd person to suggest it, and for all we know at the other end of a keyboard they might have run some tests against the ECU and found it was the fault.....possibly. I mean they have had enough time.

My suggestion would be a 1.8 ECU for as little as you can spend on it from a scrapy or parts supplier. If it doesn't fix it flog teh ECU on e-bay....

The problem Mazda have had, their diagnostic tools weren't talking to the car

The part they have changed was blown, crank shaft sensor, and the car wouldn't start without it, they had to replace that, to ensure that nothing else blew the ECU if they needed to put a new one on.

AM going to get an ECU 2nd hand, but still will have the problem of who is going to pay for the work - the AA, or the Garage (who are denying responsibuility!)

The only think that would blow the ECU is a power spike - the chances of that comeing from changing a 10amp meter fuse, is rare, unless they did it with the ignition on.

[franv8]

Allow me to suggest another hypothesis,

There is an electrical fault somewhere on the car.

This blew the ECU and the crankshaft sensor.

Fitting these two parts again may see them go the same way.

Sorry to say this, and I may be wrong (I was shocked to have found that I have been in the past...), but whoever is looking at it needs to go back to basics and check that there is not another fault before they potentially write off two more fairly expensive bits of electronics.

Is the fuse still blowing?

Does the fuse continue to blow if the ECU and crankshaft sensor are disconnected and the ignition turned on?

Be careful that if you are now paying for the garage to practice on your car at your expense, it may be time to take it elsewhere, maybe even to an auto electrician?? I will reiterate, alas I can be pessimistic on these things, they may be completely on the right track in which case I will apologise.

[ali_kat]

franv8 said:

Allow me to suggest another hypothesis,

There is an electrical fault somewhere on the car.

This blew the ECU and the crankshaft sensor.

Fitting these two parts again may see them go the same way.

Sorry to say this, and I may be wrong (I was shocked to have found that I have been in the past...), but whoever is looking at it needs to go back to basics and check that there is not another fault before they potentially write off two more fairly expensive bits of electronics.

Is the fuse still blowing?

Does the fuse continue to blow if the ECU and crankshaft sensor are disconnected and the ignition turned on?

Be careful that if you are now paying for the garage to practice on your car at your expense, it may be time to take it elsewhere, maybe even to an auto electrician?? I will reiterate, alas I can be pessimistic on these things, they may be completely on the right track in which case I will apologise.

I'm assuming this is what Mazda have checked, as they haave gone through every option before they looked at the ECU, as they have had no diagnostic tools, they have had to go back to basics.

No, the fuse was no longer blowing when it left the original garage, but then, the car wasn't running either, so it was all that was working PLUS, the original gfarage had told me that they couldn't fix it without replacing the Altenator, and then viola, they had,......

It was the AA whoo recommended Mazda over an Auto electrician, as if it were the ECU, it would need to go to the main dealer anyway.

I agree with your thought process, however, this is a car that cost me £2.5k, it now needs a £2.5k part, how much more money do I throw at it?

I guess I will know more once I've been tot hhe Dealer todayy, as I will ring the AA from there. I will also speak to my insurers today about invoking my legal cover, and see if they cover criminial damage to the car?

I spoke to Andrew at Autolink last night...... The only parts place to list having a MK1 ECU. This ECU is the only one with the imboiliser built in. And he has never been able to get one when required. Most of the MK1 cares pre '98 in the scrap/breakers yards won't have a working ECU, because of this rarity.

He also told us that in his opinion, the only ways for the ECU to be burnt out are if thhe ignition was left on withou the engine running, has been known t burn out the coil pack. Or a poswer spike.

I cannot recommend this guy highky ebnough for the knoweldge he gave us last night - at 7.30 on a Friday Really, really helpfuul guy

Am going to see if there is a local independent Mazda specialist locally that can visit the car @ Mazda/think of anything else that it could be. Because as Andrew pointed out last night, it may be that the Mazda techies haven't worked on a car of this age before, few take them back to Mazda after the warrenty has run out.

Edited by ali_kat on Saturday 27th September 07:06

[anonymous-user]

Can't you fit an ECU without the immobilser? Even if your insurance requires it it's probably cheaper to have a 3rd-party one fitted afterwards than buy a new ECU.

Autolink actually have some mk1 ECUs on Ebay at the moment:
http://cgi.ebay.co.uk/ECU-Mazda-MX-5-Eunos-MX5-com...

You could but a whole new car for less than £1k, or perhaps buy an MOT-fail for a few hundred quid?

Edited by anonymous-user on Saturday 27th September 09:52

[ali_kat]

Guys :kiss:

This morning, have been to visit my car @ Mazda. Spoke with Service Manager, who has waived the cost of the CSS so I just have the diagnostic costs to pay

They are preparing a report, which will show that the ECU's Circuit Board is blown, and has been by a power surge not due to mechanical or parts failure.

We saw the circuit board, you could smell it, as well as see an 1.5" burn mark! The Manager has said that they are happy to fit a 2nd hand/repaired ECU for us, and will try to source one for us as well

Whilst we were in there, a new Mk3 caught our eyes So we asked for a trade in cost on mine - as it is now £0. Once fixed £2.5k which is what I paid for it Proves to me I need to fix her

The AA have said that because the car did not 'die' on the road, but in the Garage, then my Breakdown Repair Cover is invaild - surprise surprise Moral of that story, next time something breaks on the car, call the AA out

In the meantime, following conversations with the original Garage owner yesterday, we rang him and told him of the report Mazda are preparing (and may have pointed out how local bad news spreads quickly ). He has spent this morning trying to source an ECU for us. He has also said that if the Mazda report implies that the ECU Circuit Board was blown by human error, he will make it good

So now I need to get the report, and then transport the car back to the Garage so he can organise the repairs

Anyone in Warwickshire with a car trailer that could/would help me with this please?

[ali_kat]

swerni said:

why don't you try phoning some breakers yards.

May save you an absolute fortune

Because having done that, most are in there with the same problem

They are, however, repairable

[Munter]

Possibly not the closest PHr with a trailer.... But Sniff does offer in his profile..

http://www.pistonheads.com/gassing/profile.asp?mem...

[ali_kat]

Munter said:

Possibly not the closest PHr with a trailer.... But Sniff does offer in his profile..

http://www.pistonheads.com/gassing/profile.asp?mem...

If no-one closer offers, I may need to work out cost of petrol vs local recovery (£60)

[Munter]

A thought on the ECU Ali. You could go for the upgrade option.

http://www.performance5.com/enginemanagement_ecus....

ummmm shiney things....



edit:
More info on the Linc ECU here.
http://www.flyinmiata.com/index.php?deptid=&pa...

Edited by Munter on Saturday 27th September 14:58

[ali_kat]

Munter said:

A thought on the ECU Ali. You could go for the upgrade option.

http://www.performance5.com/enginemanagement_ecus....

ummmm shiney things....



edit:
More info on the Linc ECU here.
http://www.flyinmiata.com/index.php?deptid=&pa...

Edited by Munter on Saturday 27th September 14:58

Erm, ££££ !!!

[MX-5 Lazza]

Actually, I know a guy who wrote off his '98 Berkeley and broke it up to sell as parts rather than fix it up.
I'll send him a txt to see if he still has the ecu

[ali_kat]

MX-5 Lazza said:

Actually, I know a guy who wrote off his '98 Berkeley and broke it up to sell as parts rather than fix it up.
I'll send him a txt to see if he still has the ecu

I think I love you!!!!

[Munter]

ali_kat said:

Munter said:

You could go for the upgrade option.

Erm, ££££ !!!

Yeah I know. It's not the cheapest option. But it is 1/2 the price of the standard new replacement from Mazda! Plus it's an asset you could sell later. But Lazza's contact / other sounds best.

[OnlyMX5ives]

Lazza if you mean SCUB I told him to keep it as they are valuable.

You need the key and ECU and some say the immob ring by the key but some say you don't.

Mazda specialists sell everything inc. lock set for around £400 IIRC as I had this with a MK2 but I was lucky and managed to get the ECU repaired.

I have a Mk2 98 ECU (and key) I presume its different but if you can get the no. off the side I'll check.

BUT I think you need to identify the cause before fitting a new ECU.

I guess ask the garage exactly what they did and check for signs of shorting.

HTH

Oh and I have a replacement Link ECU for a 98-98 if you decide to go down the modified route.

Edited by OnlyMX5ives on Saturday 27th September 23:53

[MX-5 Lazza]

OnlyMX5ives said:

Lazza if you mean SCUB I told him to keep it as they are valuable.

I do mean SCUB. How do you know Steve?
I sent him a text this morning but haven't had a reply. I'll try emailing him unless you know him better and can get in touch...

As for the key, I would have though a Mazda garage would be able to reprogram the immobiliser.

[ali_kat]

OnlyMX5ives said:

You need the key and ECU and some say the immob ring by the key but some say you don't.

Mazda specialists sell everything inc. lock set for around £400 IIRC as I had this with a MK2 but I was lucky and managed to get the ECU repaired.

I have a Mk2 98 ECU (and key) I presume its different but if you can get the no. off the side I'll check.

BUT I think you need to identify the cause before fitting a new ECU.

I guess ask the garage exactly what they did and check for signs of shorting.

HTH

Oh and I have a replacement Link ECU for a 98-98 if you decide to go down the modified route.

I have all 3 keys, and the imob number on the key ring, well mazda have atm

It is a different unit to the MK2, and the MK1 Eunos's

Mazda have spoken to the Garage and found out what they have done, checked everything except the altenator and are positive it is just the ECU from a spike

Does this help?

[OnlyMX5ives]

MX-5 Lazza said:

OnlyMX5ives said:

Lazza if you mean SCUB I told him to keep it as they are valuable.

I do mean SCUB. How do you know Steve?
I sent him a text this morning but haven't had a reply. I'll try emailing him unless you know him better and can get in touch...

As for the key, I would have though a Mazda garage would be able to reprogram the immobiliser.

I bought his coldside and 50% of the rest of the bits !

I don't think they can recode the ECU or at least not for a reasonable fee as that is what I needed... of course if anyone knows differently post up.

[OnlyMX5ives]

ali_kat said:

OnlyMX5ives said:

You need the key and ECU and some say the immob ring by the key but some say you don't.

Mazda specialists sell everything inc. lock set for around £400 IIRC as I had this with a MK2 but I was lucky and managed to get the ECU repaired.

I have a Mk2 98 ECU (and key) I presume its different but if you can get the no. off the side I'll check.

BUT I think you need to identify the cause before fitting a new ECU.

I guess ask the garage exactly what they did and check for signs of shorting.

HTH

Oh and I have a replacement Link ECU for a 98-98 if you decide to go down the modified route.

I have all 3 keys, and the imob number on the key ring, well mazda have atm

It is a different unit to the MK2, and the MK1 Eunos's

Mazda have spoken to the Garage and found out what they have done, checked everything except the altenator and are positive it is just the ECU from a spike

Does this help?

Mine is different.

No you need the ECU and a matching key - you can copy the no. to a new key to use your locks but AFAIK you cannot match a new key to an unknown ecu code.