ECU Issue

[Phaeton]

I swapped out my cam cover for a powder coated on & caused myself an issue, the orange wire which goes to the IACV grounded out which blew the 15A Engine fuse, replaced the fuse & engine now runs. The error on the OBD said P1504 I obtained replacement throttle body & IAC valve but still have the same error, I've proved the wires through from the IACV to the ECU & they are both good, so all I can think is I've damaged the ECU. I also notice now that when in gear with the clutch down the engine in longer increases in speed, whether that's related or not I don't know.

I have access to a car that's being stripped & going over tonight to remove the steering lock, key, ECU but do I also need anything else, the TRW 36A unit which I think is the immobiliser do all 3 have to be matched?

Both cars are 2005 1.8 VVT's

[Mazda Mender]

It "must " be the same number on the ECU....
Main...

ECU,
Keys,
Immobizer,
Ignition aerial ....

Secondly....

Ignition barrel,
Door locks,
Boot lock,
Glove box lock,
Arm rest cubby lock.
M-m

[Phaeton]

Thank you, when you say immobiliser are you meaning the TRW 36A unit? Ignition aerial black ring around key?

Also as an FYI I don't have

Door locks,
Boot lock,
Glove box lock,
Arm rest cubby lock.
M-m

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Once again thanks

[Mazda Mender]

Info after the question was asked, but yes you won't need the doors,boot , glove box ,centre cubby locks.
Ignition aerial is the black pick up ring for the key, immobilizer is the Lucas control box, never referred it if it is as a TRW 36A?
M-m

[Phaeton]

Once again thank you very much for your help, hopefully once installed we will be good to go.

[Mazda Mender]

Keep us up to date, and please add your car details into your profile so it locks into every post at the bottom that you do which will help us buddy.

Are you not going to tell us the story all about her? we love pics and a good nosey into what others are doing, give us your story bud.
M-m

[Phaeton]

I've been into kit car since building my first in 1981, that was a Dutton Phaeton, not sure I have any pictures of her, but looks very much like this one without the bonnet scoop. It was running a meek 1.3 Ford Crossflow but was fun, she was sold when we got married

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Then in early 2000's I built a couple of Funbuggies Freestyles

First was Mary named after using a Mary Quant Mini as a base

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Then is was Mr Bumble

He evolved over the years from running a Mini 1275 A series engine

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To having his ar*e cut off & a 1.8 K series Rover engine fitted

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Used to go on camping trips to Wales each year

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That was 2019 by which time my back was playing up due to the slightly twisted seated position, so he was sold & I went through several kist that year,

A GTM K3, a Formula 27, a Robin Hood, a Bugrat but none really fit the bill

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TO BE CONTINUED

[Phaeton]

Okay kit car history story pushed to one side for a moment as we get back to my real issue, back story car was running fine without any issues. I had a camshaft cover & inlet manifold powder coated which once fitted I ended up with a P1345 error, which I took to be that the camshaft sensor wasn't sitting correctly, I removed the cover again & ensured the sensor fitted correctly, on refitting the P1345 had gone but replaced with a P1504 the car would still run but a bit hesitant around 2.5K I tried to drive over to my sons 20 miles away when the engine cut completely, not even any ignition or EML light on switch on. On investigation it was the 15A Engine fuse replacing it got it running again, I also found where the Orange wire looked like it had rubbed on the engine lifter bracket which is the IACV.

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It still has a P1504 error which is IAC Electrical Load Failure so I swapped out the throttle body & IAC for another known good one, the error remained, also proved the wires through, also noticed that now if I put the clutch down & put it in gear the revs didn't increase, don't know if that is relevant. I figured I fried the ECU so today I fetched another ECU, immobiliser & keyset.

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Fitted the new ECU etc. with the new ECU it starts but I get the errors P5162 ECM Battery Back-Up Voltage Low along with a pending EGR Valve Motor Coil 4 Open Or Short. Strangely the clutch in gear is now working as it should

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I'm now even more confused how 2 separate ECU's can bring up 2 separate sets of codes?

[Phaeton]

So just to prove I did use the search function which I why I much prefer forums to Faecesbook hopefully the answer is here

viewtopic.php?t=6486
https://mazdamenders.net/forum/viewtopic.php?t=2976

I'll be checking the 4AG pin later

[Phaeton]

Okay update on the update which hasn't been approved yet, after reading the other posts I went in search of the 4AG terminal, I had a good 12.6V static & 14.8V running, so opened the ECU up to be greeted with

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Touched the pin for this to happen

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Got out the soldering iron & did this

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So for now I have powered the ECU direct from the 10A Room fuse

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[Mazda Mender]

So at some point in its life it as gotten wet, and you are dealing with the aftermath of it having a toe in the water, great searching to find the fault ,
But you are better off getting a new(second hand) good working clean ECU and fitting it rather than creating washing lines everywhere, because that ECU is going to give you a lot more electrical headaches over time, get rid, put another in and forget it, is my 2 pence worth on this.
M-m

[Phaeton]

Yeah it's a bit annoying that my original ECU is perfect & it's the replacement that's been a submarine, but at least I know all my wiring etc. is all good. I'm thinking of Supercharging or Turboing over winter at which point I'll go ME221 or even 442 so need a solution until/if I do. I've found another ECU about 40 miles away but the lad's away until the weekend so I'll have a play to fix the 4AE pin but probably fetch the replacement.

Is there anybody who repairs ECU as the alternative would be to get my original one looked at

[Phaeton]

Anyone know what the voltage that should come out of 4AE, I have a constant 4.29V?