Broken Mk1 Mx5 PCM signal - help required please!
Discussion
ali_kat said:
Cheers Guys
It goes the moment I turn the key
Tis a UK not an import
It affects the Rev counter, Oil Temp and warning lights too.
10amp fuse, and no, am not going to put a 15 in
Am a girlie, don't have a garage or equipment
Looks like she is off to the Garage then
Its very unlikely that you've got a problem with the gauges, its likely that its something indicator related.
Have any of the indicator lenses got water in them? Check the wiring that goes into the back of them and follow this back as far as you can.
Do you have a wiring diagram? I've found one here
http://www.madracki.com/miata/images/wiring/90diag...
Is the fuse blowing when the indicators and hazards are off? If so then its not a fault with the wires going to the bulbs and for now these can be ruled out. If it goes only when the indicators are turned on then its either the flasher unit or a fault related to the indicator bulbs or the wiring going to them.
Its unlikely that its the wiring going to one of the gauges, so my best guess is that its a fault in the flasher unit or the wiring that goes to it. Flasher units are usually very easy to replace and this would be my first choice.
Hope that makes sense, PM me if you want some more fault finding help.
ali_kat said:
spikeyhead said:
lots of stuff
Kev, read whole thread 
I started my reply before you added the latest info in. Got very distracted on the way so took far longer than it should have done.
Hmmm, so car did have a minor electrical fault, garage repairs that and in the meantime it develops a major fault. This may or may not be the fault of the garage that were fixing the fault and its not going to be easy to prove whether it was a random failure that occurred whilst the car was in their care or if its down to their actions. Your AA cover may help with this.
Autolink 
They have most parts for most years on the shelf and are reasonable priced.
Edited to add: You could probably get an ecu off them on the basis that, if it doesn't fox the problem you can return it - it's worth asking anyway
They have most parts for most years on the shelf and are reasonable priced.
Edited to add: You could probably get an ecu off them on the basis that, if it doesn't fox the problem you can return it - it's worth asking anyway
Edited by MX-5 Lazza on Wednesday 24th September 21:24
spikeyhead said:
Arse,
I started my reply before you added the latest info in. Got very distracted on the way so took far longer than it should have done.
Hmmm, so car did have a minor electrical fault, garage repairs that and in the meantime it develops a major fault. This may or may not be the fault of the garage that were fixing the fault and its not going to be easy to prove whether it was a random failure that occurred whilst the car was in their care or if its down to their actions. Your AA cover may help with this.
Not quite my words I started my reply before you added the latest info in. Got very distracted on the way so took far longer than it should have done.
Hmmm, so car did have a minor electrical fault, garage repairs that and in the meantime it develops a major fault. This may or may not be the fault of the garage that were fixing the fault and its not going to be easy to prove whether it was a random failure that occurred whilst the car was in their care or if its down to their actions. Your AA cover may help with this.
Mr AA Man said that the AA will (obviously) try to wriggle out of paying, and who can blame them
Personally, am kicking myself for not calling the AA out in first plave - but seriously, who wood for a fuse/Short circuit??
I need to get the Mazda garage to make a clear blame in their report - age, or Garage. Personally, I would prefer age, but that is because I like the garage guy
See what tomorrow brings, alhtough I do still want to know the legal implcations if anyone can help?
But has been taken to Mazda, so this option not available If you give them a 2nd hand part to fit instead of new they will have to fit it. They can refuse to fit it but they shouldn't as they will still be charging labour which is where they make most of their money anyway. If you make it clear you can't afford to pay for a new ecu that should help make up their minds
MX-5 Lazza said:
If you give them a 2nd hand part to fit instead of new they will have to fit it. They can refuse to fit it but they shouldn't as they will still be charging labour which is where they make most of their money anyway. If you make it clear you can't afford to pay for a new ecu that should help make up their minds
I may have to pull that one
Diagnosis => Labour = £70/hour + VAT
Senior technician has been working for an hour, and is stumped. Has sent out for technical help from other Mazda dealers
AA say, if a valid claim, they will pay for diagnosis, and repair, upto £475 (value of BRC)
If not a valid claim, I have to pay
Interestingly, Mr Garage Man has rung me this morning to ask after the car - good customer service, or guilty conscience?
Wigeon Incognito said:
If you're having trouble physically removing the fuse, find a co-worker with a Porsche (a BMW would probably do too, maybe other German cars).
They all have fuse pullers in them, either in the tool kit or clipped in the fusebox like mine.
My rover and mondeo both had fuse pullers.They all have fuse pullers in them, either in the tool kit or clipped in the fusebox like mine.
I still have back pain from replacing my flasher relay
Ok, Mazda hope they have found the problem!!!
They say there is no signal from a PCM to an RPM or the Cat so I need a new Crank Position Sensor, which hopefully will solve the problem
Tis coverd by AA BRC, as if this is the problem, it has gone due to age and just a coincidence that it went in the Garage If not, then back to the drawing board
They say there is no signal from a PCM to an RPM or the Cat so I need a new Crank Position Sensor, which hopefully will solve the problem
Tis coverd by AA BRC, as if this is the problem, it has gone due to age and just a coincidence that it went in the Garage
If not, then back to the drawing board The new sensor hasn't fixed the problem
But it has used the AA donation up, so now this is my money being spent
I now have 2 Mazda technicians looking at my car @ £70 per hour
There is no signal coming from the PCM - anyone got any ideas please?
They haven't tried the ECU, as rare that they go and they don't keep them in stock.....
But it has used the AA donation up, so now this is my money being spent
I now have 2 Mazda technicians looking at my car @ £70 per hour
There is no signal coming from the PCM - anyone got any ideas please?
They haven't tried the ECU, as rare that they go and they don't keep them in stock.....
Edited by ali_kat on Friday 26th September 11:15
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?
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?
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