CorradoWannabe 1 Posted January 15, 2012 My car is not starting at the moment and we've traced the issue to the voltage supply to the ECU. The Emerald ECU has an LED that should be red when the ignition is on - but it does not come on. Been checking fuses & relays - but they were fine - then measured the voltage with the ignition on. Measuring a wire going in to a pin that is labelled in manual as 'Igntion Sesnse Input' that says it needs '+12v supply via ignition switch' it is only getting 5 volts though. Another pin labelled '+12V ignition supply' is also only getting about 5 volts when in the ignition position. The battery is giving 12volts when measured directly. Can someone confirm ignition output should have 12 volts when in ignition position and NOT 5 volts? Any ideas what could be causing the drop in voltage? Quote Share this post Link to post Share on other sites
CorradoWannabe 1 Posted January 16, 2012 Anyone know what could causing the above? Could it be the ignition switch? Quote Share this post Link to post Share on other sites
mikkijayne 0 Posted January 16, 2012 The ignition output certainly should be 12V, not 5. Where are you taking the supply from? Quote Share this post Link to post Share on other sites
CorradoWannabe 1 Posted January 22, 2012 I started looking at this from the ECU back - so the measurement I took was from the actual pins on the loom that plug in to the ECU. I've not traced that wire fully, but it should be wired to the ignition circuit. Below are what the manual says pin 11 & 28 should have - right now I read 5.5 volts at the loom for both pins 11 | Ignition sense input | +12v supply via ignition switch 28 | +12v Ignition supply | Supply from main relay or common with pin 11 Tried a new ignition switch yesterday - but no better. My dad is going to trace the wire through and try and follow it through to see if we can find a bad connection somewhere or something. Any ideas / hints / hunches appreciated! Quote Share this post Link to post Share on other sites
nrc 0 Posted January 22, 2012 I read a bit ago about someone finding a break or nick in the insulation of a wire which had allowed the conductor inside to corrode and introduced a voltage drop. Something to look out for when tracing the wire, I reckon. Quote Share this post Link to post Share on other sites
CorradoWannabe 1 Posted January 22, 2012 Spent some time looking at this today - got very excited when I found the earth connection from batter to ECU was not fully tightened on to the battery terminal. Worked with my dad to clean up the contacts and put it all back and tried - still only 5-6 volts in to ECU. We found another relay in the engine bay - part of the Emerald install we think - and there was a fuse connected inline. I'll post pictures of the connector - and the fuse we found inside. With that cleaned up and fuse replaced, the ECU light was working! Fuel pump was coming on - fuel pressure was also showing up on adjustable fuel pressure regulator.... tried starting it.. it turned over - but still did not fire :( progress though! We suspect the crank position sensor - and want to look at that next - I'm frozen and in quite a lot of trouble with the missus - but hoping it will be worth it when it is finally sorted!! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted January 23, 2012 Glad you're getting somewhere with it. That melted fuse certainly looks like a likely suspect. Not wishing to be rude, but that and the other wiring I've seen in your thread worries me :? If you would like some help getting your loom tidied up to a more acceptable standard, I am happy to advise. As I said on the R32OC, you need have your laptop connected and in the diagnostic page whilst cranking. You will soon see if it's picking up the crank sensor or not. If it can't see a signal, you won't get any fuel or ignition. Quote Share this post Link to post Share on other sites
CorradoWannabe 1 Posted January 23, 2012 Ahhh, Corrado32 = FishWick! Yes, now the ecu is getting correct voltage and turning on the 'live adjustment' page should do the trick. Just need to find some time to give that a go, supposed to be moving house this week! Thanks for the offer about the wiring, I'd definitely like to take you up on that offer, will PM you Quote Share this post Link to post Share on other sites
CorradoWannabe 1 Posted January 25, 2012 Car fired up!!!!!!!!!!!!!!!!!! The fuse was the root issue, just gave it another few cranks today and it fired up!! Leaving it with my dad who is wants to tidy up the electrics before I drive it. So pleased it was just the fuse and no major sensors etc! Quote Share this post Link to post Share on other sites
