intermittent electrical faults (ecu)

[rampage89]

OK, ive been getting random and intermittent faults and problems for some time now, and am now stumped for ideas.

First problem was intermittent starting and engine cutting out, i had a diagnosis done by auto elec but they couldn't find anything wrong except for the ecu power supply pins were scorched a little.

So i got a new ecu from wreckers and was fine for about a month. Until last week all of a sudden it got hot, i realised the thermo isn't coming on unless a/c is on. And also the oil light is coming on intermittently(oil level fine, no knocking in engine). And just last night with the lights on there was no dash lights at all.

I tried the old ecu and it isn't doing the old cut out problem but is doing the same faults as the new one.

I'm bringing it down to either the ecu, ecu power supply(where ever it is?), or bcm.

Any ideas would be great, as i need to get the car reliable before i travel back to QLD in a couple of months.


Cheers Dan

[kopper69]

I dont know but I think you might be in the wrong direction. Car cutting out is normally the CAS, and you can normally pick this by checking the error codes.

If two ECUs are doing the same thing it probably isnt the ECU. They are fairly reliable too.

Dash lights - start by checking fuses and swapping relays - park lamp relay too. Simple electrical fault should be easily tracked down by any auto electrician if you want it fixed fast.

Oil light, maybe a new oil pressure switch, cheap and easy to replace. Tied in with the DFI module, which could also be causing the car to stall. CAS sends its signal to the DFI module so what may look like the CAS can sometimes be the DFI module.

Power to the ECU is by fuse 10, 7.5A fuse. I would be checking that as it is tied in with the interior lights too.

[rampage89]

alright I'll check that out to. if not i might get another diagnosis done while its still showing faults.

cheers

[hako]

Also check the earth to the ECU.

[Haydz]

Also check the earth to the ECU.

which one is this?

[hako]

The black wire.

[Haydz]

obviously..


but where abouts does it ground too. my understanding would be it grounding to the front of the motor on a v6

[specter]

ON a VS 6cyl ( which MAY be the same ) rear of passenger side head has a couple of earths as well.