Hey guys, I've got a 2008 cobalt sport 2.4, been a great car and I haven't always been the nicest to her. The other day I had my tires changed, I went for lunch, then to the girlfriends. While I was waiting for her I shut off the car for maybe 5 min. When she came out I tried to start it, nothing. Battery is good, tried boosting, cleaned all cables, relocated grounds. Tested battery at work, and trickle charged for 12hrs. Tested the starter by pulling crank relay and sending power to the starter with a power probe, it cranks over the engine no problem. Checked all fuses, and relays and all good. I did notice though that my engine harness had rubbed through onto the oil filter housing, and rubbed through a blue wire, of a twisted pair (blue & light grey) I believe this is a CAN ? goes directly to the ECU. Is it possible that it shorted to ground and fried the ECU? If so, how do I go about replacing this? If I have an exact model number, from a 2.4 of similar year can I just plug and play? Does it have to be from a 2.4 can I use from a 2.2? (2.4's pretty rare around here, especially in wreckers) or do I have to have it flashed? I also noticed that my info display is showing --- instead of actual readings and coolant temp is reading -40c

Any help would be EXTREMELY helpful, if I hadn't just put $600 into tires I would probably not be bothering with this any longer, but it had to happen after I spent the money so I need to figure this out. Preferably sooner then later, and as cheap as I can.

Thanks guys

 

First i would start with repairing the wires, youre correct that the twisted wires are network wires which can easily cause the car not to start.

The 08 le5 and l61 cobalts use the same ecu but you would have to have it flashed by a dealer.

 

I fixed the wire but I think the ecu is fried already. Would an ecu from another vehicle like a Malibu or something with the same ecotech in it? Would it run before i have it flashed ? Just poorly and with codes or? I just don't want to have to tow it to dealer just to have it flashed and hope it fixes it

 

Just check the part number on the ECM, make sure it is the same as your cobalt.

 

Ok so I've got the can line fixed, I went to the wrecker I got an ecm with the same serial number. Replaced it. Also replaced the fuse box under the hood. I start it up I have dash gauges now as well as info display. And in able to hook up a scanner and it connect to ecm. Unlike before . I get code p0315 crankshaft position system variation not learned. And it still won't start ideas?