No start.... Again
 

I'm going to start a new thread, because I feel that this is not related to my previous problem outlined in this thread https://www.cobaltss.net/forums/prob...s-hell-319229/

Car has been in storage since november. For the first month of storage, I would start it up and drive it around the storage facility just to keep it moving around. but ever since mid December I havent been able to get the car to start. Turn the ignition on, ABS light and Traction Control light stay on. Go to start the engine and nothing happens. I get a click coming from underneath the dash (near the BCM) but the engine does not turn over.

My first suspicion was the battery. Checked the voltage, it was low at 11.69. Pulled the battery out and charged it at home. was able to charge it to about 12.6 volts. Put the battery back in the car, with no success. Had the battery load tested. Still put out 594 CCA's.

Every fuse was changed in the car this past summer. No idea what to check at this point. I'm considering pulling out the fuse box today and making sure nothing is loose, and checking for any corroded contacts.

Any ideas?

I cant believe no one has suggested the ignition switch. Was a really common problem on the older cars 03-05. My 04 ion had that issue. Wouldn't crank, the passlock symbol would flash. A random amount of time later I woud try again and it would start right up.

my buddys 05 has been doing this. good to know

Clutch position switch is a cheap thing to replace and could be the problem. It also may just need to be adjusted

in my friends case, he already replaced that lol

Its a good idea also to check all the connections leading up to the starter. Mine was all corroded and needed to be cleaned.

Also there's no benefits to starting your car up during storage. Doing more harm than anything.

Starter is the first thing Im going to check. Hopefully the starter is just dead. Im sick of chasing electrical problems. I should be able to get the car towed back to my house by march so I can get to work on it.

I was told by the garage I purchased it from that the ignition switch was replaced.

Big fuse off the rear battery pressed in tight? It can rattle out.

I just started my car for the first time in 4 months, booted right up!!. Best of luck

I actually changed that fuse this past summer due to some discoloration on it. so thats not a problem.

Pulled codes today. U2107 U2105 U2129. Had a few others that were stored. But those three kept coming back. No abs code. Actually I was getting no communication with the ebcm. Using what we will call a "Tech 2 equivalent" cough cough.

Im getting a high resistance on the HS-CAN, pin 6 and 14 on the dlc. Should be 60ish ohms, im getting over 120 ohms.

Definitely a module issue IMO. You can try jumping the HS and LS CAN wires at each module to bypass the module to get your resistance back in spec. Last time I had a problem like this it was the comm. module under the drivers seat. Granted this was on a aveo. But it was an intermitten no start that was really pissing me off.

But it was the same thing. High resistance at the dlc and I by passed modules until I found the one that got me back in spec. Replaced and programmed the module and problem solved

Just disconnect the connector at the modules and connect yellow to yellow and purple to purple until your back in spec. I'd start at the ecbm since you can't connect to it

But why would the power steering module itself have U2107 and U2105 codes? if theres a fault in the power steering module would it block communication with the EBCM?

I'm not sure what those codes are but they're communication codes, shouldn't have any affect on connection with the scan tool. May not let you view certain data though. Just do what I posted and see where it takes you.

The problem your having is literally identical to the one I had on that customers car. Intermittent no start, high resistance on dlc, that what I did and I was able to find the problem

I think one code was no communication with bcm and the other was no communication with the ecm. I'll try jumping the EBCM like you described. If the module is toast I would assume its a dealership only job correct? Thanks by the way!

You can replace it yourself but it will need to be programmed. There are some independent shops like mine that have flashing equipment, but if not then yes the dealer is your only option.

Just bypass the modules one by one until your resistance specs goes back to normal at the dlc

At that point it should start with it bypassed

I'll give it a try.

Any idea where i can find a pinout diagram for the ebcm?

Unplugged EBCM and still had high ohm readings. Unplugged power steering module and couldn't get any ohm reading at the dlc. Now the battery is pretty dead.

You need to jump the CAN lines or resistance won't change. Low speed is yellow, high speed is purple. Just jump the yellow to yellow and purple to purple at the connector, so your essentially completing the circuit manually instead of the module doing it. Plug each module back in after your done as they are all in series.

That was the plan lol Im looking for a pinout diagram for the ebcm connector. none of the wires are visible.

If you can't find one, I'll get one when I'm back at the shop tomorrow