Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

2015 Silverado Flashing Check Engine Light - No Engine Power

Recommended Posts

Hi all,


I have had my 2015 Silverado 5.3L Crew for less than a year, purchased February 2015. Currently, the truck has around 14800 miles on it, most of which are highway miles as I make frequent trips between Atlanta and Florida. Today on my way to work in Atlanta my truck just gave out on me power wise, no acceleration passed 40 mph. The check engine light came on and started flashing repeatedly which the Chevy site indicates that to mean there is a serious problem that needs immediate attention. Well I was a very short distance from the dealer near work so I just maintained my speed and tried not to let the truck shift gears. Once I got off the highway I had to come to a stop and experienced really rough idle and some hard knocking sounds. The truck did not however seem like it wanted to die out or stall on me. When the light turned green I pressed the gas and had very weak acceleration, the truck was hardly picking up speed and I couldn't tell what the trans was doing. Anyway, I got it around the corner to the dealer and dropped it off.


I am hoping its just a computer module or something that gave out and started affecting things but it honestly seems more to me like a serious mechanical issue. Does anyone have any similar experiences or have any speculation into the issue? The transmission in this truck has always been the thing I liked least about it, sluggish shifts, not knowing what gear it wants to be in, hard shifts and knocking/dropping sounds. Any info or experiences would be appreciated.




Link to comment
Share on other sites

When the light flashes like that it means some sort of mechanical damage is occurring. It also puts the truck into limp mode which is why you had no power.


You really should have pulled over, shut the truck off, and called a tow.

Link to comment
Share on other sites

I have a 2015 LTZ w/ less than 5K miles and my truck did this to me at 80MPH on a busy highway. I was lucky enough to get off the road enough to prevent an accident. Had to be towed to the dealer as it would not start after that. It ended up being the high pressure fuel pump and the part had to be ordered. Once we got the truck to the dealer, it would start but extremely rough idle. Pretty sad for <5K on the vehicle. Runs fine after the replacement though and I really do like the truck. We'll see how it hold up over the long haul.

  • Like 1
Link to comment
Share on other sites

Thanks for sharing your experience. Dealer got to my truck late in the day as they had existing jobs that needed finishing. They said the knock sensor went bad and that threw of the timing of the engine. I'm not 100% that's the full issue but I will provide an update after they get the part in on Monday. For now I am in a cute little Chevy Sonic as it was the only loaner they had left haha



Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

I find it hard to believe a knock sensor caused the issue. The only thing the knock sensor does is tell the ECM if a knock event is being heard, if it does it will put the truck into the low octane timing map until the knock event goes away. It will retard the timing as well, but even at the max retard values I have seen the truck should have still been driveable and not in limp mode.


Hopefully they will have more thorough news today for you.

  • Like 1
Link to comment
Share on other sites

So I picked up the truck from the dealer last night and I instantly noticed a difference in idle and ride quality from the month before leading up to the problem. It was like I hopped into a new truck after the dealers repair. I don't see any mention of replacing the knock sensor in the work order like they had originally mentioned but the mechanic replaced 4 lifters that went bad. I was asking him about the cause of the problem and he pointed me to a service document GM has open for the 5.3L engines (which matched my conditions and issues):


I have attached a section of it below.


Engine Misfire/Tick Noise, Malfunction Indicator Lamp (MIL) On, DTC P0300 Set



Some customers may comment on a malfunction indicator lamp (MIL) on and/or an engine misfire/tick noise.

Technicians may find DTC P0300 set or in history.



This may be the result of an active fuel management (AFM) lifter that is mechanically collapsed and/or stuck all of the time.

This may be the result of internal locking pin damage in the lifter. Due to oil aeration.



If SI diagnosis does not isolate the cause of this concern, technicians should inspect for valve operation.

If the valve(s) are not moving, replace the valve lifter oil manifold and affected bank of AFM lifters. Refer to Valve Lifter Oil Manifold Replacement and Valve Lifter Replacement in SI.

If the lifter has spun the bore, the guides should be replaced also.

Edited by jbreeds09
Link to comment
Share on other sites

  • 2 months later...

I find it hard to believe a knock sensor caused the issue. The only thing the knock sensor does is tell the ECM if a knock event is being heard, if it does it will put the truck into the low octane timing map until the knock event goes away. It will retard the timing as well, but even at the max retard values I have seen the truck should have still been driveable and not in limp mode.


Hopefully they will have more thorough news today for you.


Do you happen to know what "engine map" the truck reverts back to every time you start it? For instance if you put a lower octane fuel in and the knock sensor has to retard the timing will it stay that way indefinitely or can it sense when higher octane fuel is added on lets say the next fill-up.

Link to comment
Share on other sites


Do you happen to know what "engine map" the truck reverts back to every time you start it? For instance if you put a lower octane fuel in and the knock sensor has to retard the timing will it stay that way indefinitely or can it sense when higher octane fuel is added on lets say the next fill-up.



On start up the truck will be in the high octane map until a knock event is detected, then it will drop down to the low octane table and stay there until the event decays out. There is also a table for E85 as well that is used if the alcohol sensor detects enough alcohol in the gas.

Link to comment
Share on other sites

  • 1 year later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Content

    • By Jake_Melvin1
      I have a 2020 RST with the 3.0 LM2 Duramax with 79k miles… the flywheel failed when I was driving down the highway and left me dead in the water.. I had it towed to the dealership 4 weeks ago and they called today and said the transmission and the engine needs to be replaced. Has anyone experienced this with their trucks? I never towed anything heavy and was religious with service.. luckily all covered under the 100k powertrain warranty… 
    • By Sir_Griglesworth
      Hello everyone. I've recently purchased a 2020 Silverado 1500 from a dealership. I found out late in the sale that the truck was used as the dealerships "loaner" which didn't really bother me even though I know people beat up those vehicles. Anyway, I'm pretty in-tune to vehicle sounds and I had a couple of questions regarding noises I'm hearing from my vehicle. 
      The first is a clunking noise and a physical jolt when I shift from Drive to Reverse. I have my foot on the brake and am on a flat surface. I notice it a lot after I've been driving for a while and go to back into my garage. I took the truck back to the dealership and they chalked it up to bad U-joints. They slapped 2 fresh sets on, but I've still go the issue. Any ideas what it may be? I don't feel like anything is going to fail, but I also don't like the sound and don't think it should be that way. I have another service appointment next week and I'd like to help them out with ideas considering they don't really seem to care.
      The second is a ticking noise coming from the undercarriage. I' got under the truck today and believe it's coming from the rear portion of the engine, but I'm not for certain as I've never been beneath the truck while it's been on a rack. The noise cannot be heard when standing at the front with the hood up, but I can hear it very noticeably when standing at the driver's door. I do not hear it as the engine is heating up, but that could be because every other component under the hood is loud as h*ll while the truck is heating up. Once the engine is approaching operating temp, it's very noticeable. As you can hear from the short video, it's every .5 to 1 second or so and is always present during idling. Again, may not be a big issue, but I hate hearing things on my vehicles that I can't attribute to something else.
      Thanks for reading my ramblings. I can try to post longer videos if anyone needs. Thanks in advance!
      IMG_8898_Trim_Trim (2).mp4 IMG_8910_Trim (2).mp4
      So I have a question don’t get on me for being dumb just want other opinions.
      I have a ls2 swapped rado bought the truck on a deal only problem was I couldn’t drive it for more than 20-30mins without getting trans hot on the dash and would go into limp mode but if you cut the engine off for a minute or two and cut it back on message went away for another 20-30mins but the actual trans temps never hit about 180 
      this is where it all starts.
      anyway 1blown torque converter later and a trans rebuild my transmission guy told me the genius put a 2500 ecu in just to get the truck to fire up with a slight tune that pulled like a F****** freight train back to the point he tells me the truck thinks is has a 4l80 in it witch It doesn’t I have a 4l60 he said I needed to take it to a tuner shop asap so I don’t blow my trans or torque converter again because there’s a lot of major differences mainly being gear rations and shift points 
      witch I thought a tune would fix anyway but I wasn’t for sure so I got the truck tuned by Powerfab autosports and they reflashed the ecu programmed it and did a dyno tune 
      when I pick up the truck the dude shows me the power chart and the truck made 280hp 360tq
      witch I think is way ****ing off but I am not a master mechanic I know a lot about vehicle but not enough to be firm on saying that’s bullshit 
      Why I needs y’all’s insight is because when the truck was ****ed up and giving trans hot display on dash the ****** was a ****** Ton faster and pulled a boat load harder the ass would squat the truck would drop a gear and scream so beautifully she would literally throw me back in my seat and keep in mind this is with 305/35/24s  now it’s just feels like I have a slightly beefed up 4.8 
      engine mods are air intake long tube headers full exhaust trans cooler and that’s pretty much it as far as I’m aware 
      does anyone know or have any insight as to what is going on and why I am making such low numbers or where the **** my power went?? 
      and I would appreciate no assholes just need some info thanks! 
    • By AaronandAlicia Dailey
      OK everyone I want to give thanks ahead for any advice and help.
      Truck in question= 2003 Chevy Suburban Z71, 5.3 L         Transmission= 4L60-E
      So the story started when I was going down the road at about 50mph in cruise control, when suddenly I heard the engine begin to rev up. I hit the brake to take it out of cruise control and the engine stopped revving up. Apparently I lost transmission of power from the engine to the wheels because no matter what gear I put it into now, I get no movement from the vehicle. No reverse and no D1, 2 or 3. When I put the vehicle in park and attempt to push the vehicle it will not roll. When placed in any other gear I can then roll the vehicle freely.
      Before this happened: Since owning the vehicle 4x4 has always been shifty.....hehehe...sorry couldnt help it. I have the model where there are 4 buttons with lights the buttons are located left hand of dash near the turn signal. When I first got the truck sometimes it seemed like it didnt want to switch between gears. for example I would have to hit the button multiple times before it would switch and even then it seemed like it hadnt really switched but the lights would indicate it had. Most of the time the light for the button I selected would flash multiple times and then return to previous selection. Often times after turning the vehicle off and then returning to vehicle to go somewhere I would find that the light has switched back to a gear that it wasnt in when i left the vehicle. It seems to favor 4x4hi. As of lately I havent been able to get the lights to switch at all. It seems to be stuck in 4hi permanently.  
      I have tested the 4wd switch and its fine. 
      I tried unhooking battery for half hour with lights on to reset PC. I then reconnected battery cable and turned vehicle on but not start it. Then I pulled a bunch of fuses and plugged them back in. ( seen it in a video and the guy said it was supposed to wake up the TCCM) Well that did nothing. 
      I have the truck off of all wheels right now and was trying to figure out if the transfer case is stuck in neutral. With the truck in drive as I turn the rear draft the front moves also. I am assuming that means it is in 4wd. But should I have someone hold the front drive shaft while i turn the rear drive shaft to confirm its not just from friction or something.
      I actually have the front drive shaft partly out right now in an attempt to get at and remove the shift motor and manually put the transfer case into 2hi.
      I am also considering changing out solenoids. I have gathered it is unlikely the shift solenoids. Is it possible it could be one of these:
      1 * EPC (Pressure Control) Solenoid
      1 * PWM Solenoid
      1 * Manifold Pressure Switch
      1 * TCC Solenoid w/Harness
      Another thing I suspect which would be an easy fix is the transfer case fluid level. I removed the fill plug and nothing came out. I can tell it has been leaking. I would have already topped it off but I have been stuck at home (no running vehicle lol). Could low fluid cause this issue? I hope that's all it is lol. Anyways I got a ride to the store tomorrow and to look at a back-up vehicle. Anything you guys recommend to grab from the parts store while I'm in town tomorrow?
      What would be your guys recommendation on how to solve this problem and fix it?
      All help is appreciated.
      thanks in advance,
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    Total Topics
    Total Posts
  • Member Statistics

    Total Members
    Most Online
    Newest Member

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.