No Start -- Need Help!

[mja31]

Hey folks, may I have a little help, please?

My 2011 SS convertible won’t start. I’ve been sifting through various old posts trying to diagnose and troubleshoot, but I’m coming up empty. Here’s what I’m working with, and what I’ve tried so far:
Current Symptoms:
1) Turn key, no start. No noise, starter not engaging.
2) Dash lights: Service Stabilitrak, Service Park Assist, Low Fuel (don’t think I’m low on fuel, but possibly could be)
3) Scan tool code: U0100 – Unable to communicate with PCM. x3.
Other possible symptoms:
1) This past summer, would randomly get a no start, but would start fine normally on 2nd turn.
2) Over past year, would randomly (but more frequently lately) have shift issues from 1st to 2nd (manual trans) even when I shift above 20 mph, above the skip shift threshold.
3) Have always randomly had dash message pop up “press clutch to start engine.” Always ignored it b/c I never had trouble starting the car when it popped up.
4) Last drove car in December when it was insanely cold. Went on a 1,000mi round trip to Michigan, so was driving in snowy/ salty conditions. Did wash the car before driving home, including undercarriage. Drove a few days back home right before New Year’s, w/ no problem. Took a flight out of town for a week, and when I tried to start it up in early Jan. hasn’t started since.
Tests/ diagnosis completed:
1) Originally suspected the starter w/ intermittent no starts recently and all the talk about the general Camaro starter issues. Replaced starter with an MSD Dyna-Force.
2) Tested battery, battery is good. Had Auto Zone charge it up. Even bought a new battery just to be totally sure, and returned it when ruled out as the problem.
3) Checked main starter/ ignition fuses and relays in main fuse block. I think there may be a few other ignition- related fuses in the instrument panel and trunk I could check.
4) I’m not an electrical expert, and it’s been a few weeks so don’t remember everything, but I did use a test light on the new starter and it checked out. I did not check resistance yet when ignition key turned.
5) I only found one main engine block ground on the front passenger side. I cleaned the contacts, but I don’t have corrosion issues. The car is mostly garage-kept, rarely driven in shitty weather, and is very clean w/ about 72k miles. Question: Where are the other major grounds located, aside from the battery ground in the trunk?
6) Wiring harnesses all seem to be in check – don’t notice any corrosion, frayed wires, etc. Any recommendations on specific harnesses/ connections to check without checking every single one?
7) I tried some backwoods shit, like adding 2 grounds from the engine block to the chassis using jumper cables. I did not yet try adding the permanent engine ground near the starter w/ the 0 gauge wire. I also did not yet try bypassing that positive jump start terminal in the engine compartment.
8) I did get desperate at one point, and tried that bizarre clutch position sensor paperclip bypass hack. I did unclip the harness to try the hack, but did not replace the sensor yet. I’m assuming that I do not have to do a relearn by just unclipping the harness, correct? Then again, I wouldn’t get any relearn instructions to pop up on my scan tool since I can’t get communication w/ the PCM.
9) My battery and PCM contacts are in great condition, but did apply some delco silicone grease sparingly to those contacts.
10) My last ditch effort was to buy a “plug and play” PCM online from Flagship 1. Not sure of their reputation, but I submitted my VIN, so the company was supposed to be able to bench program the PCM, and I’m supposed to just be able to do a key relearn.
11) Got the new PCM yesterday. As part of the anti-theft/ key relearn, I used the Passkey III procedure. The key is to be inserted, and turned to ON position for 10 minutes, or until the red dash security light goes out. But when I insert the key into the ignition, the red security light does not show up. On one attempt, I locked the doors with the FOB, security light comes on, but as soon as I insert the key into the ignition, the light goes out.
12) With the new PCM, I still have the dash warnings (service stabilitrak, etc.).
13) I tried to plug in my scan tool with the new PCM, but still get the no PCM communication message, and it still won’t clear.

I'm really trying to avoid having the car towed to the dealership.

Any advice, please? Really appreciate it!

-Matt

[swampcritter]

Check your ground wire in trunk

[mja31]

I checked and cleaned the battery ground in the trunk, it was in good condition. I checked the trunk fuses, all were good.

No change in status.

Any other thoughts?

[gtstorey]

Sounds like this is going to take a methodical electrical diagnostic. You've tried most of the basic "my car didn't start and this fixed it". If you are going to fix this yourself, time to start studying voltage drop testing and also getting the OEM wiring diagrams.

[SS_Don]

Since it’s a manual maybe you could push start it. Then you could drive it to a repair shop.


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[mja31]

Thanks, folks.

Instrument panel fuses were all good.

I like trying to figure things out, plus I'm a cheapo, but I guess if this is a needle in a haystack thing, it's time to call the tow truck.

Will let you all know what they come up with.

[HyperV117]

Hope you figure it out. Mine had an odd issue and it turned out to be the ground on the driver side. I just put a fatter cable in from the block to the body of the car and that fixed it. Super weird.

I followed this video

[csymes15]

Did you ever figure this out?
I am having the exact same issue on my 2014 and have been running through every idea I can before sending it to a shop
any help/advice would be great

[carjockey71@gmail.com]

Did you figure this issue out yet- I have 2012 CAMARO SS 6/ SPD and I have would, did you get hard starting issues before this happened ?

Give you a example, I have had the car almost 9 years with almost 95K for the last year after I run it for a couple hours and shut it off, if I try to immediately start it again it doesn’t want to start, I have to either what until it cools down (around 50 mins and sometimes in Florida that’s not long enough either, and who has that kind of, most of the time after the 2nd try it will start but if I don’t wait a hour or more the whole left side of my dash lights up, telling me the stabilitrac is off, tractional control is off (IE PUTTING IT COMPETITION MODE same as turning the options off right under the gauge display above the shifter) I tried disconnecting the positive on the battery, negative, BOTH and nothing would happen. he car would run like it was recammed, it sounded mean it awesome but it was hesitant, jerky acceleration, etc., off course if I let the car sit I could disconnect the negative on the battery and that would it out, occasionally I would get a check engine, feeling me to replace the crank sensor., but still has the issues, I had read about doubling the battery cables and that is suppose to take remove this hard start issue, I have also seen articles about removing the ignition fuse, etc - I have had a lot of luck with removing the K50 relay and putting in one that I carry with with me and switching them, the one in the engine e compartment is always so hot I have to believe there is a more serious problem but it has been working for me, I don’t have hard starting and if I do I replace the relay and start it over and the everything is normal again - or as normal as constantly swapping rely should be (it’s ridiculous and it is not something you should have to do, but there it is.

In you case I would check your neutral safety switch, depress it and check your voltage to the starter, double check all your fuses and relays and put the original computer back in your car, I have had the ‘depress clutch’ issue a handful of times, I believe you can remove a remove a fuse for that and I have never been stuck - I would also recommend plugging back in the lead you disconnected, also maybe replacing the crank sensor or a combination of things, I believe these are a lot of electrical gremlins with these cars.

Let me know how you make out - message me

[csymes15]

My issue is not a hot start issue
it just wont start at all
I have replaced the starter, added additional grounds from engine to chassis and battery to chassis, checked every fuse in all 3 fuse boxes, used multimeter to verify power to fuse box and starter, replaced the battery with a brand new one
I have gone over the entire wiring harness that is visible and verified that there are no splits or worn wires
removed ECM and ABS connections to verify there are no broken pins
Still nothing

One major difference is that when I plug an OBD2 scanner into the OBD port it says it can not connect to the vehicle

Car has run perfectly fun until this happened the other day, managed to get it to start and run once after trying 4 or 5 times, moved it to a better location, and have not been able to get it to start since

anyone ever had any similar problems?

[TooCool5]

Originally Posted by csymes15

My issue is not a hot start issue
it just wont start at all
I have replaced the starter, added additional grounds from engine to chassis and battery to chassis, checked every fuse in all 3 fuse boxes, used multimeter to verify power to fuse box and starter, replaced the battery with a brand new one
I have gone over the entire wiring harness that is visible and verified that there are no splits or worn wires
removed ECM and ABS connections to verify there are no broken pins
Still nothing

One major difference is that when I plug an OBD2 scanner into the OBD port it says it can not connect to the vehicle

Car has run perfectly fun until this happened the other day, managed to get it to start and run once after trying 4 or 5 times, moved it to a better location, and have not been able to get it to start since

anyone ever had any similar problems?

Do you get any lights when you turn the key?
Could it be a transponder chip issue.
Did you try another key?
There is a sequence to be able to do a key relearn to re set the ECM per your current key.

[csymes15]

Originally Posted by TooCool5

Do you get any lights when you turn the key?
Could it be a transponder chip issue.
Did you try another key?
There is a sequence to be able to do a key relearn to re set the ECM per your current key.

Tested with multiple keys
They are working fine but car wont start
We are individually testing all the modules rn
So far tested bcm, abs, and power steering and they are not the problem
We think it's the ecm
Need to run another test to make sure but that's what we have narrowed it down to

[csymes15]

I have been running all kinds of diagnostics and am now to the point where I believe the bcm might be fried
I will be installing a new one this week and I will let you know if it works for me

[csymes15]

so new BCM was swapped in
car now starts but still having communication issues
some modules are communicating but not all and the dash is lit up light a Christmas tree
ran continuity tests to rule out broken wires
now looking to replace EBCM and PSM to see if they will restore communication
honestly pretty stumped at this point