SO I finally have my first issue that is not a quick fix.. (fixed, starter relay)

I was driving my car and it lost power. It was still running, but would not go over 2000 rpm, safe mode?

I coaxed it to work, and when I tried to restart it, nothing. I have done ALL the normal no start stuff. but can't get it to crank and fire by the key. I have no wiring diagrams the show the start signal circuit.

As it sits, it will crank over with the relay jumped. Everything else works with the key on. The ECU scan tool says the clutch is depressed and the start signal is being received, based on the fact I can crank it with the jumped relay and it sill doesn't start I believe there is not fuel or spark. But since its not cranking but the ignition, I am not working on that issue, what ever is keeping it from cranking would keep the other things from coming on. I already replaced the ignition switch.

The ECU scan says the signals are going, I can hear some relays clicking, but I can verify which have power or not when (going to do that tomorrow).

Anyone have a wiring schematic of a 09+ aveo signal circuit? And the ign2 circuit which i believe turns on fuel and spark?

the other tech in the shop thinks the battery died and killed the ECU, i put in a junkyard ECU and no change. At this point he feels it is either the ECU program or a bad harness. Both are dealership trips and $$.

anyone have any other ideas?

It sounds like you are headed towards the mercy of the Chevy dealerships and the girls from GM who only offer kind and gentle, apologetic words. Unfortunately, kind words have never solved any automotive problem.

Meanwhile, I'll add thoughtful words: Check that wiring harness again, and any others that might pertain. A bad connection might be the cause.

Here are the wiring diagrams for the starting and charging circuits in the 09. Hope this helps.

If it's not what you need, let me know and I can see if there is something else appropriate.Attachment 8542Attachment 8542

It sounds like what happened to me before my piston blew up. To be sure, I'd pull the sparks and see if there is a wet one. I found this out because I did a weekly engine clean back before the piton went. If there happens to be a wet spark, it could be that the piston isn't fire correctly, or even at all. A piston not firing would lead it to go off time and cause serious damage.

EAD15 That last one looks like what I was missing, and the zip file has everything else. I at least know where to look now (could not associate the correct grounds to check off the computer, etc. Thank you.

Gramble, the car won't even signal the relay. If i jump the relay, it cranks fine. But the cranking is futile because the signal to send spark and turning on the fuel pump is not there.

Hopefully this is just a ground issue, or something. I doubt I am lucky enough to be able to get the ECU to start sending signals out without a trip to the dealer though. Same issue with the 2nd ECU installed. Will post what it is if I find it.

I'm not entirely comfortable offering advice because you're the pro and I'm just a shade tree DIYer, plus you said you tried all of the standard no-start stuff as well. But I just can't get past the battery (or far less likely, a bad AVR in the alt) as the prime suspect here. So I guess I'll just go ahead and ask my dumb question - did you try another battery?

I replaced the battery yes, but not with a new one but a tested good one, going to try a new one before the dealership because I'm not paying them a diagnostic fee to put in a battery either.

I put in a new ignition switch, it did not help.

I put in a used ECU, since it said the signals are there. But do not seem to exist to the components. It did not help.

Scan tool comes up with every circuit "working" I can see the % values of the pedals, the switch, etc.

Did not get a chance to work on it today, going to check the common ground by the computer for the relays. But that wouldn't answer why the signal is not getting sent to the relay. Which still points to ECU (even with the new one).

I wish I had something useful to add rabbit. So are you seeing the same symptoms as you saw with the previous ECU?

You know it got real when Rabbit is stumped.

put a new battery in, removed and cleaned all the grounds, tested to wires for continuity, still nothing when key is in start, no relays for the fuel pump, engine main, start/crank have signal power. I even searched through TSBs for the cruze, sonic and spark hoping to find something similar. I had it towed to the dealership. Its either something really stupid, or the ECU. The mechanic will probably join the forums to find a fix.