After re-fitting my ECU the Z is dead!

On turning the key the red diagnostic LED comes on and stays on. Is this right or should it go off/flash?

I replaced the ECU chip with another (known good) chip but it didn't work. Tried putting the original back and it's still the same. I've done this a few times before with no problems.

I hope it's just a loose wire somewhere...

 

Chris, make sure the plug is not screwed in too tight but tight enough!!!

 

Just hope you haven't blown any components on the main board or blown the chips. Did you make sure you grounded/earthed yourself before messing with it?

 

Yes, took anti-static precautions as usual and now i'm stuck not knowing if its the ECU thats died or a broken/loose wire on the harness. Why does it always get dark just when things go wrong? I need the Z for a 160 mile round trip tomorrow morning. Bugger!

 

Usually if you turn on the ignition with no ECU eprom then all the fans start running, this is kind of a default state for the ECU. Does that happen ?

Is the big blue ECU plug seated properly ?

Did you get the eprom the right way round ?!?

The blue plug is firmly in, the EPROM is the right way round and has been all the time so I know that it is not the chip that has damaged something. I have tried 3 differnet chips too. I used to repair motherboards and all sorts of other electronics stuff so I know what i'm doing but just can't understand why it's stopped working. If it's a dodgy wire on the blue plug it will be an impossible job to trace back for a break.

Which fans come on with no ROM fitted?

I might try taking it out to see...

It doesn't help having Traction Control, Speedo Converter and HKS ALC all wired in around the same area - looks like a pile of spagetti.

 

 

[This message has been edited by ChrisC (edited 13-01-2002).]

The electric sub fan in front of rad comes on and stays on when in default, what's the engine trying to do, is it trying to start ?? or not even cranking over ??

smithy

The engine will crank with the ECU removed (not just the eprom), but it won't fire.

 

You should be able to bypass the TC easily by fitting the two white plugs together - if you fitted tehm.

 

Without the eprom the a/c fann will be running and possibly the electric fan too.

Thats interesting...

All the dash lights come on as normal but when I turn the key it's totally dead - doesn't even make a click or turn over.

Almost as though my imobiliser is still active but I don't think there are any connections to the alarm down there...

 

It's a bit late to do anything now but I'll try removing the TC, ECU then the ROM to see what happens some time tomorrow.

I left the ECU out of the car overnight. I wonder if something has upset the alarm/imobiliser?

I tried removing the battery for a few minutes to reset everything but no luck.

Thanks for the info chaps.

 

 

[This message has been edited by ChrisC (edited 14-01-2002).]

I have unplugged the ECU but it's exactly the same - dash lights come on as normal but nothing fires/turns over when I turn the key. No fans come on.

Any ideas?

Could it be a fuse somewhere?

I'm going to test em all but a clue would help!

Need to get it sorted this weekend.

 

Chris I could come over,and you could try my ecu my car is UK will it fit?

 

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As far as I know it will fit...

It's okay to swap ECU's from jap to UK, but if manual to auto then, ONLY to see that the car fires up, check relays in box behind passenger headlight and then the ones in drivers footwell if another ECU doesn't work.

smithy

MAC1 is coming to my rescue (hopefully)

At least it will rule out the ECU.

I think we both have auto's...

WELL chris very strange? So we put my ECU in Chris's car and NOTHING! put his ECU in my car and WHEY up it fires first turn There is nothing at all when you try and start his car not even a click.starter? immobiliser?

 

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Thanks Iain,

Must be a loose wire to the starter circuit or my alarm/imobiliser. Another option someone mentioned is the starter inhibitor circuit on an auto which won't allow it to start unless in park/neutral. Checked all fuses OK.

At least I know the ECU is OK £$£$£.

I can now look forward to tracing wires all day tomorrow :-(

 

Ok Chris let me know how you get on with it on Sunday .

 

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Sorted!

Many thanks to Aaronjb.

It turned out to be the auto starter inhibitor circuit which the muppet who fitted my alarm/immobiliser system chopped into and connected up with a naff joint.

Took 4 hours today to trace back all the wires which had joints into them.

Must have broken free when i moved the harness on the ECU.

Major relief!

 

 

[This message has been edited by ChrisC (edited 20-01-2002).]

Nice one Chris, great to hear that you've sorted it.

 

I know how you feel as we've had the same with Mrs. Turbos car! Very frustrating to say the least!

 

Nice one Chris Big releif it was not the ECU.

 

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