Intermittent engine light

[SonicSW20]

That'll do it.

Has the fluid damaged any traces? If so you may need to put some jumper wires on there too.

[DaveWS]

I tried that, basically the engine light flashes constantly at first, and then the light turns solid (matching it turning on when not in diag mode). It doesn't throw up a code

Weirdly if I remove the paperclip with it running and reinsert it again, the engine rpm picks up for a few seconds then bogs right down to 600rpm or so. I guess the diag mode is only for when the engine is off because it seems to mess with the fuel mix or something.

Diag mode is used to set ignition timing, it puts the timing into static mode so a drop in RPM is normal.

Clutching at straws really... Have you removed the ECU and taken the cover off to inspect the board? They're at that age where capacitors fail which can cause all sorts of odd issues.

Yeah I already opened up the ECU and replaced both 10mF capacitors to fix another problem months ago (engine wouldn't start when hot) - I also had to repair a corroded trace.

I've inspected the rest of the ECU pretty closely and I don't think there's any further damage, but without another working ECU it's hard to know for sure.

[Pauln]

Long shot, but it's a double sided PCB, did you solder the capacitors on both sides?

Paul

[DaveWS]

I opened up the ECU again today and added several more jumper wires to every connection which might have looked even a tiny bit suspect (even though continuity was fine). Still the same

Could it be an earthing issue somewhere?

[DaveWS]

Checked and cleaned several earth points in the engine bay area and still the same problem. Anyone know of a used ECU for sale? Just so I can rule it out. P/N is 89661-17380. There's one on eBay currently, I've messaged the seller to ask about the caps...

I also think this fuel pump relay must be related somehow. It switches on or off when the engine light turns on. I can't find any over here for sale though. P/N is 28380-74050

[SonicSW20]

FP to B+ in the diagnostic port bypasses the relay doesn't it, and just supplies full power to the pump at all times? If thats the case then you can do that and see if the problem persists.

[DaveWS]

Hmm, just tried that and it makes the relay go nuts, makes a screeching sound.

Tried disconnecting the relay completely with the jumper trick, car starts and runs, but sure enough after 10-20 seconds the engine light still comes on!

I bought that ebay ECU, so will swap that out in a few days time and see what happens. Christ this is something else lol

[SonicSW20]

The relay makes a screeching sound? That doesn't sound right, but at least that test rules it out as being the cause of the EML issue.

I can't understand why there's no code stored though.

[DaveWS]

Replacement ECU arrived and installed, and no engine light! No idea what could still be wrong with the old one then, I've repaired all the traces that look remotely damaged and replaced all the capacitors which I had spares for.

Thanks for all the help in this thread, I would have gotten a replacement ECU sooner but there were none about until just a few days ago.

I've also still got an intermittent horn (mostly doesn't work but occasionally does!) to fix...

[ribbo]

I've also still got an intermittent horn (mostly doesn't work but occasionally does!) to fix...

*innuendo claxon*

[DaveWS]

Haha very good.

[SonicSW20]

At least its sorted! Yeah, Gen3 3SGTE ECU's don't come up all that often and people often want silly money for them.

[DaveWS]

Bump - I've started another thread because I still can't fix the fecking horn forums/viewtopic.php?p=1708203

[markstevieandmads]

At least its sorted! Yeah, Gen3 3SGTE ECU's don't come up all that often and people often want silly money for them.

his ecu was a rev 2 turbo according to that ecu number. Even more common for the caps to blow

[hojoos]

Could be lambda related?