2010 camaro ss2 L99 multiple codes lights flashing won't shift out of 1st

[67cc]

Hi I'm new to the site so I hope this question is in the correct thread. Just bought a 2010 ss L99. Little background on car. 112k seems well maintained lots of receipts one previous owner stock execpt for exhaust and new bmr poly motor mounts. All was well for the first couple weeks. Then 2 days ago the service stabilitrac light came up then parking assist, check engine light, abs, e brake lights all popped on. Then the temp oil rpm and speedo stopped reading. Also wont shift out of 1st gear...I freaked. So, after I came back from the edge I started with the code reader, wont connect to give codes. Says CanBus a lost communication. I tried multiple readers so its not a reader issue.
I did some research here on the site, found a few things that seemed simi related. Started with battery just put in a new one as old one was 5 years out. Checked connections at battery and checked every fuse in all 3 areas (underhood, dash, trunk) no baddies. Checked grounds and wiring to and from ecm under hood.
Plugged in code reader was able to pull codes
P1682 replaced electronic ignition switch
U0733
U0700
U0109
So as it stands now, car starts but will jog through the rpm range, run rough, or run smooth all on its own. Also wont shift out of 1st even in manual mode. Back to not being able to read codes at obd port and guages flutter between working and not working (cluster lights up).
My thought is it a bad ecm...but I don't want to just throw parts at it. Last resort is the dealership or auto electric specialist..
Anyone else experienced this?
Sorry for the long description just wanted to pass on as much info as I had.

[67cc]

Correction on codes
P0700 lost communication with tcm
U0073 no communication with can bus a

[Tothefloor]

I just purchased a 2010 SS at auction and it had not keys so I didn’t even know if it ran. Had someone come out the program a new key but when he connected to the car he saw all kinds of error codes. So he was unable to setup the key. Later I remembered watching something on YouTube about having the boards relearn. I disconnected the positive and negative cable from the battery and shorted them together. This drain the capacitors in the broads and they start a relearning process. I was just throwing ideas around and it worked . I was shocked but maybe it will help you until you have a chance to catch the real problem.

[67cc]

Hi, thx for the response. I will try that shortly. If it works I will post it. I also noticed the date on the display is 3/11/2009. Which i assume was its initial program date. Fingers crossed

[NOT A 45]

Originally Posted by 67cc

Hi I'm new to the site so I hope this question is in the correct thread. Just bought a 2010 ss L99. Little background on car. 112k seems well maintained lots of receipts one previous owner stock execpt for exhaust and new bmr poly motor mounts. All was well for the first couple weeks. Then 2 days ago the service stabilitrac light came up then parking assist, check engine light, abs, e brake lights all popped on. Then the temp oil rpm and speedo stopped reading. Also wont shift out of 1st gear...I freaked. So, after I came back from the edge I started with the code reader, wont connect to give codes. Says CanBus a lost communication. I tried multiple readers so its not a reader issue.
I did some research here on the site, found a few things that seemed simi related. Started with battery just put in a new one as old one was 5 years out. Checked connections at battery and checked every fuse in all 3 areas (underhood, dash, trunk) no baddies. Checked grounds and wiring to and from ecm under hood.
Plugged in code reader was able to pull codes
P1682 replaced electronic ignition switch
U0733
U0700
U0109
So as it stands now, car starts but will jog through the rpm range, run rough, or run smooth all on its own. Also wont shift out of 1st even in manual mode. Back to not being able to read codes at obd port and guages flutter between working and not working (cluster lights up).
My thought is it a bad ecm...but I don't want to just throw parts at it. Last resort is the dealership or auto electric specialist..
Anyone else experienced this?
Sorry for the long description just wanted to pass on as much info as I had.

This is extremely hard to explain to a layman, but I will try. You will need a voltmeter capable of reading resistance to diagnose this. Fortunately, the high speed communication network on this car is pretty small and only includes 6 different modules.

So briefly and explanation of how the system works. Your modules communicate with each other over 2 wires that go from module 1 to module 6....they go to a module, through it and continue on to the next module until reaching the last one. So they are all interconnected. So now kind of like christmas lights, we have a complete circuit from the first module to the last. Starting with the first module in the circuit (usually the ecm) a 120 ohm resister is placed between the 2 wires. At the very end of the circuit either in the last module connected or just after it a terminating 120 ohm resister is placed between the 2 wires. This is for diagnostic purposes. Without going into ohms law or going into an electrical seminar a complete unbroken circuit going through 2 120 ohm resistors is 60 ohms. A broken connection or wire on either leg of that 2 wire circuit will read 120 ohms.

So with what we've learned here is what you need to do. Disconnect the battery, wait 10 mins. Take your volt meter set to ohms and probe terminal 6 and terminal 14 of the under dash diagnostic connector. This is that 2 wire communication circuit we just talked about. On a good car you should read 60 ohms +/- If your reading around 120, there's a break in the circuit somewhere. Even if you do read 60, you could have a intermittent bad connection. Here's how you diagnose. While watching your meter go to each module and wiggle the harness....disconnect and re connect and see if your reading changes. Chances are you will see something unless a wire is broken in which you will have to do different diag that I don't have time to explain and is probably over your head anyhow. But this is something simple that anyone can do and usually isolates the problem.

I hope this helps. After you do this a few times it's actually pretty easy. Communication codes seem intimidating but there actually not once you know how the system works. Good luck!

[gtstorey]

http://resources.aeswave.com/ATG-05_...%20may%20occur.
This has a pretty good description of how the data circuit works and contains the test that not a 45 describes.

[67cc]

Thanks for the info. I will be working on the car over the weekend. Will update as I move forward.

[67cc]

Hi, so I figured I would follow this up once more now that the problem has been determined. Not a 45 gave solid advice. The procedure is a bit beyond my skill set so I took it to a local reputable auto electric service. Not the cheapest, but after about 6 hours he contacted me with the diagnosis of a bad tcm in the transmission. Or more accurately a faulty tcm, he described the process to substantiate the diagnosis. Same as Not A 45, so once the tcm was isolated and bypassed the car returned to normal all lights and gauges function car drives smoothly. Shifts fine. He determinedthat there is probablya bad ground or sodder connection on the tcm inside the transmission. So...maybe this will help someone else maybe not...thanks to all on the thread for your time and knowledge.

[NOT A 45]

Originally Posted by 67cc

Hi, so I figured I would follow this up once more now that the problem has been determined. Not a 45 gave solid advice. The procedure is a bit beyond my skill set so I took it to a local reputable auto electric service. Not the cheapest, but after about 6 hours he contacted me with the diagnosis of a bad tcm in the transmission. Or more accurately a faulty tcm, he described the process to substantiate the diagnosis. Same as Not A 45, so once the tcm was isolated and bypassed the car returned to normal all lights and gauges function car drives smoothly. Shifts fine. He determinedthat there is probablya bad ground or sodder connection on the tcm inside the transmission. So...maybe this will help someone else maybe not...thanks to all on the thread for your time and knowledge.

Awesome....even some of the guys I work with struggle with communication issues.