Jump to content

Recommended Posts

Posted

Towed to dealer says it started. 2019 Silverado RST Crew 5.3 left me stranded at zero degrees.  I pressed the start button and the starter cranked at high rpm without the bendix engaging to crank the engine.  I had to press the button to stop it from spinning.  Tried several times still only starter spinning.  Roadside tow last night to dealer.  Dealer said started fine had a few codes ie fuel pump etc.  said come and get it NPF.  Now that is disappointing from a reliability trustworthy stand point.   Curious if anyone has heard of this symptom.  3024 miles on vehicle. 

Posted

Yes, cars have done this from the inception of the electric starter.

 

 

The fix is to crawl under there and hit the starter with a hammer.

  • Like 2
Posted

Spinning without engaging has NOTHING to do with it being a push button.

Both the key and push button systems (and also the remote start, for that matter) just send an input to the computer.

 

As raisedbywolves pointed out, the starter drive not engaging (resulting in a free-wheeling starter) has always been an occasional problem.

 

The hammer certainly isn't a 'repair' solution, but sometimes it will get you home.

 

I think I'd be pissed that the shop just gave an NPF diagnosis. 

Posted
1 hour ago, RaisedByWolves said:

Yes, cars have done this from the inception of the electric starter.

 

 

The fix is to crawl under there and hit the starter with a hammer.

I always carried a hammer in my old Diesel VW Dasher....  got me out of quite a few jams...    even better, always tried to park on a hill whenever I could :)

Posted (edited)

So I press the brake pedal and press and release the start button and the starter free wheels for ever until it burns out the starter or I press the start button again to stop the starter.  I have never turned a key to start any vehicle and and released the key and it kept free wheeling.  If a new Push button start GM vehicle has no flywheel engagement the starter can spin itself out of control with no fail safe?  Unless grandma Mabel figures out she has to start the vehicle again to get it to stop trying to start?  Odd. At no time is the engine running.

Edited by 19RSTZ71
Posted

I’m sure there’s some kind of cranking time limit built in, but it’s probably higher than most people would be comfortable with letting it run out.

 

Either way, there’s not much difference between having a key or push button besides the different motion. GM vehicles with keyed ignition have only required a “bump” of the key for years. Bump the key to the start position and the engine would continue to crank over until started. You’d still have to intervene or it would just keep cranking without holding the key there.

Posted

Boeing and Hitachi were pretty sure about things as well.  I appreciate the reasonable responses so I’ll just note that I threw the penalty flag while standing outside of my 3,000 mile new truck listening to the starter spin until I jumped back in and stopped it.  I will update this post should a software anomaly with the start stop remote start systems be tied to some of the codes present.  Might be more to it.  It starts ok today repeatedly with no service performed.  Thanks all. 

Posted

I suppose I could have.  May still need to.  I spent 30 years in my past life working with factory auto engineers from the field sharing and convincing them there was something brewing and contributed to numerous factory TSB’s.   It always blew me away how they would quietly share back that “This is a problem”.  There were many issues where I was the first to ring the bell.   I now know very little but that same alarm goes off. 

  • 1 month later...
Posted (edited)

Just had the same problem with 2019 Silverado. Spinning starter with no engagement. Three hours later when tow truck arrived of course it started. I have appointment in a few days with dealerships and I will repost their prognosis. 750 miles on this truck.  Should not have this problem 

Edited by Robert Wigand
  • 8 months later...
Posted

I have a 2019 Sierra and it won’t start at all it doesn’t crank the dash lights will come on as well as the radio but then turn back off a mechanic said it could be a short circuit somewhere but idk what to do at this point or how much it’s going to cost 

Posted
On 10/7/2020 at 9:31 PM, Jessica92 said:

I have a 2019 Sierra and it won’t start at all it doesn’t crank the dash lights will come on as well as the radio but then turn back off a mechanic said it could be a short circuit somewhere but idk what to do at this point or how much it’s going to cost 

Not at all the same issue.  You should still be under warranty so bring it in

 

On that note, I DID just have the exact problem mentioned above and CEL light

  • 8 months later...
Posted

My 2021 5.3 with 7000 miles did this to me today.  Tried four times.  Sounded like an electric machine gun until I buttoned it back off.  Let it sit a few minutes and it fired up like there was nothing wrong.  Hasn’t done it since,  but now my confidence level is out the window.  What if it works a while and then strands me in the middle of nowhere by some fishing lake?  Totally blows.  Any updates?

Posted
On 7/9/2021 at 4:53 PM, Theynine said:

My 2021 5.3 with 7000 miles did this to me today.  Tried four times.  Sounded like an electric machine gun until I buttoned it back off.  Let it sit a few minutes and it fired up like there was nothing wrong.  Hasn’t done it since,  but now my confidence level is out the window.  What if it works a while and then strands me in the middle of nowhere by some fishing lake?  Totally blows.  Any updates?

There are other threads on this subject as it relates to 2021 trucks.   The problem in this thread seems to be about the bendix gear not engaging.   Your problem sounds more like the one I have had on my 2021 3.0 diesel.   The starter engages but the engine will not fire so it just cranks until the ecu times out the starter at about 15 seconds.   The problem appears common on both gas and diesel trucks.    GM is aware of the problem but they have not issue a fix and the dealers are clueless.    Search something like "Cranks over but will not start"  or "Starter times out".

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Latest Articles

  • Posts

    • If everything checks out at the MAF, then the MAF is BAD, new or not.   You don't need a signal generator to troubleshoot this. PCM needs ALL powers and ALL grounds able to light a halogen headlight bulb - if it can light the bulb bright, then the wiring is good enough to run the PCM.   Best thing you can do for yourself is spend some time here: scannerdanner.com - Check out all his YouTube videos on similar issues. If you decide to subscribe it's the best bang-for-buck ratio in the automotive world, hands-down. He's got TONS of free vids on YouTube, too.
    • Yes, I used my multimeter to probe all of the wires at the MAF, both with the sensor connected, sensor disconnected, key on engine off, key on engine running, etc etc etc. I probed all of the wires again at the PCM, at the connectors, etc. All voltages are what they should be according to the service manual/wiring diagrams. All grounds are good, less than 20 millivolts from the battery negative under load. Both at the connector of the MAF, at the PCM connector etc.      I know this throws a pretty big wrench into things, but this truck was acting up before the swap. I don't have very much information, if any on what was causing it, but if you cleared all of the dtcs it would do the same thing where it would crank, fire, then die. And it would do the same thing a dozen or so times, and eventually it would start and run, but the difference is that it would run and actually be drivable. Whereas now if you can drive it at all, it goes into reduced power mode almost immediately, and even then it's not running correctly. When you come to a stop at a light it stumbles down to for 500 RPM before catching itself and returning to the smooth idle. And if you go more than about 50% throttle then it immediately goes back to doing the misfire thing.    Like I said, I know that throws a wrench into things, and unfortunately I was not able to pull any data or anything like that before I did this work, so I don't have much to go on.    I'm trying to not fixate on one particular thing as the cause of the problem, but it seems like all avenues are pointing me towards the PCM. Like I said I have tested the wiring extensively (see above), and during cranking the sensor does produce seemingly legitimate values at least according to my multimeter, but as soon as the engine fires those values quickly descend into gibberish. I've tried it with multiple different known working sensors, I have done literally every test I can think of multiple times on the wiring (probing the signals, probing the pins with the sensors unplugged, probing the pins at the PCM, voltage drop, voltage drop under load, continuity, ohms, and double-checking everything against the wiring diagrams/ proper values in the service data.)    Another thing that pushes me towards a possible PCM failure is, I have noticed in troubleshooting a little bit taking a break and coming back, that when I leave the truck to sit for a while and cool off, it starts and runs smoothly when I first start it up. However once it warms up. It starts having problems. For example, when I went out to the truck this morning after it had been sitting overnight, I was actually able to drive it down the block. And then once I got on the throttle a Little bit after going about a thousand ft, it started misfiring again. I pulled it back into the driveway, shut it down, and started it back up. It idled smoothly. As soon as I touched the throttle it did the misfire thing again. From then on as soon as I started it it would misfire. I shut the truck off and went to go get a coffee and do a bit more research. When I came back out I started the truck up and it immediately went into the smooth idle. After a couple of minutes of playing around with it, it would not idle smoothly anymore. Let it sit a couple of hours, rinse and repeat. This makes me think with temperature change something is going wrong inside the PCM. I have the PCM out of the 2007 donor vehicle and I'm thinking of getting a one-day subscription to the ACDelco programming service to try and program that and see if it helps.   Like I said, I'm really trying to not fixate myself on one potential cause, but it seems everything is pointing me towards PCM failure. I would really like to try to confirm that, but unfortunately I don't have an oscilloscope or a signal generator to do the GM service procedure where you feed 5 khz into the signal pin. 
    • Ahh, sorry about that - I got some bad info. Newdude is correct. That's what I get for working 13 hours straight ... on my "vacation", lol.   Should've checked the files I had instead of the internet.   Anyway ... this is GREAT news, since this would've been an absolute friggin nightmare to get working.   I don't think the lack of VVT is causing this - you've got another issue. Wiring, I'm betting.   I'm telling you right now, your computer isn't bad. If it worked before the swap, it's working now. You need to do some more (better) diagnostics and figure out exactly what you're missing. Did you test every wire directly at the MAF? Have 5V reference? Ground? If you're reading ZERO g/s, your Hz isn't much use - it's going to be the wrong value anyway. The MAF is not working, and you need to find out WHY.   I got this off the net, so VERIFY first: Pin A: Black (BLK) wire, Circuit 552, serves as the Sensor Return (Ground).  Pin B: Tan (TAN) wire, Circuit 472, carries the Intake Air Temperature (IAT) signal.  Pin C: Yellow (YEL) wire, Circuit 492, is the primary MAF Sensor Signal output to the PCM. Pin D: Pink (PNK) wire, Circuit 339 or 539, provides Ignition 1 Voltage (Power).  Pin E: Tan/Black wire, Circuit 552 or similar, often associated with the Intake Air Temperature ground or signal return.  Global-A list: https://postimg.cc/KKJnQC85    
    • Correct....the end user can't reach to Realtruck directly like they can if they purchase a Bak, Undercover, etc...  It has to go through a dealer.
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...