Jump to content

Recommended Posts

Posted (edited)

2020 AT4 carbon pro w/ 6.2L.  Threw a code and took it into the dealership.  Replaced the fuel control module.  Couple days later I walk out and the thing won't start.  Cranked but wouldn't turn over.  Check engine code said an issue w/ with the steering column sensor.  They ordered the part and I have been waiting for it to come in.  Oh yeah....1400 miles.  No faith in this truck, can't wait to see what goes wrong next. 

Edited by mg2020at4
Posted
On 1/12/2020 at 4:53 PM, Cb2 said:

Thanks for heads up, had same issue with my factory floor liners.  Couldn't get to start, just cranked with no fuel.

Guys this does not make any sense, how could the floor liner being on the gas pedal cause the engine to turn over but not start? I intentionally pulled the factory floor liner out and tossed it back in on top of the gas pedal and mine starts, there has to be more to this? Is it just a coincidence and people are being told that is what it is maybe? The scenario of the floor liner just does not make sense!

Posted
On 3/10/2020 at 2:46 PM, mg2020at4 said:

2020 AT4 carbon pro w/ 6.2L.  Threw a code and took it into the dealership.  Replaced the fuel control module.  Couple days later I walk out and the thing won't start.  Cranked but wouldn't turn over.  Check engine code said an issue w/ with the steering column sensor.  They ordered the part and I have been waiting for it to come in.  Oh yeah....1400 miles.  No faith in this truck, can't wait to see what goes wrong next. 

Got it back from the dealer with a replaced sensor.  Couple days later....won't start.  1600 miles!

 

This is phenomenal.  I should have never got rid of my toyota. 

Posted
On 3/10/2020 at 1:46 PM, mg2020at4 said:

2020 AT4 carbon pro w/ 6.2L.  Threw a code and took it into the dealership.  Replaced the fuel control module.  Couple days later I walk out and the thing won't start.  Cranked but wouldn't turn over.  Check engine code said an issue w/ with the steering column sensor.  They ordered the part and I have been waiting for it to come in.  Oh yeah....1400 miles.  No faith in this truck, can't wait to see what goes wrong next. 

Those carbon pros are beautiful, but ya this gen is the faultiest I have seen yet. 

Posted
19 hours ago, Pinnacle said:

Those carbon pros are beautiful, but ya this gen is the faultiest I have seen yet. 

Thanks.  I love the thing when it works.  Truck is still in the shop.  They acknowledge an issue but can't figure out whats causing it.  

Posted (edited)

UPDATE:

19 days in the shop in the first two months of ownership and I still don't have my truck back.  This is phenomenal. 

Edited by mg2020at4
Posted (edited)

For those of you getting this problem - the codes in the ecm are the Fuel Control Module and the Steering Column sensor.  Both have been replaced multiple times on mine.  I went to pick it up from the repair this AM and on the first start it did the same thing and threw a code again.  GM has no idea what is causing the problem and are just throwing sensors in.  So my car is back in the shop and now the fuel control module code came on.  Thats four repair attempts on a truck with 1600 miles and purchased in the end of January.  I smell lemons.

Edited by mg2020at4
Posted

Same exact problem for me. 2020 Trailboss, 1800 miles. Got in after work and wouldn’t start (couldn’t hear the fuel pump). Came back the next morning and it started right up. Now left wondering where it’ll strand me next.

Posted
On 4/3/2020 at 8:51 AM, Convoytrucker said:

Same exact problem for me. 2020 Trailboss, 1800 miles. Got in after work and wouldn’t start (couldn’t hear the fuel pump). Came back the next morning and it started right up. Now left wondering where it’ll strand me next.

They are replacing the wiring from the steering column sensor to the ecm or whatever now.  This was the "fix" from GM HQ.  We will see what happens when its done..

Posted
1 hour ago, mg2020at4 said:

They are replacing the wiring from the steering column sensor to the ecm or whatever now.  This was the "fix" from GM HQ.  We will see what happens when its done..

Interesting.. I’ll update with what the dealer tells me when it goes in this week. Hopefully they come to the same conclusion. 

Posted

well, get it in so they can fix it so you can be happy again.

 

  • Like 1
Posted

I have a 2020 Sierra with the LM2 diesel. At 150 miles it stalled while driving and multiple crank-no starts. Sounds similar to other posts. Dealer replaced the crankshaft position sensor and has new fuse box ordered. Will see what happens next. 

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

    • I thought I was building a HD 3500 srw, maybe I was lost.
    • No doubt, I definitely agree with you. However, considering the 6.2 and 3.0 have been catastrophically failing with very little miles, I figured I would put trouble free. I’m at 18,4xx and still not a single issue.  
    • It’s never dry here but it gets hot. My 4 vehicles I keep at home drive an 18 mile loop. One 6 days a week. Two about 3 days each and one once a month. Only one goes on trips about 4 times a year 1000 to 2000 miles each time. One 26 years old gets driven once a month for 22 years. One 14 years old goes 6 days a week. The other two are recent at 2 and 4 years. All are performing normal no extra service other than that would be half of recommended or severe service in the maintenance manual. No extra water or steam out the exhaust or premature plug wear. I would consider an 18 mile loop would be enough. So apparently once a month at 18 miles for 22 years has kept the collector car running well. About 45 minutes a month. 
    • It is working as designed.  NHT and non NHT trucks have the same exact transmission cooling setup.  NHT just gets a larger radiator.     The transmission cooler loop on these is as follows.     -Transmission out goes into an oil to water heat exchanger (item #1 in the first illustration below).  This exchanger has engine coolant opposite the transmission fluid and uses engine coolant to warm and then regulate the transmission fluid temperature when its in the operating window.   - From the cooler it goes to a thermal bypass valve (item #11 in the 2nd illustration below).  If the ATF has not reached the temp to open the bypass (194F), it loops back.   - When it reaches 194F, the thermostat opens and ATF then flows out to the oil to air auxiliary cooler (item #17 in the 2nd illustration) at the front of the truck.  From there it goes back to the transmission.     Your only fix would be to swap for the PPE thermal bypass delete block which will open the loop to the aux cooler all the time.  It will STILL run warm, probably 170-200F, but that's as low as you'll get it as its still flowing through the oil to water exchanger.      
    • Most say the oil temperature needs to above the boiling point of water to rid it of moisture and long enough to dry it. Many think that is about a hour at 212 F or more. Those people have never line dried cloths in a Midwest winter. Leave a pan of water sitting on the counter and eventually it all evaporates. So heat drives the time it takes. Water in oil under 175 F, the Nitration initiation temperature, is a minimum then for temperature and samples I've done that use Karl Fisher method say about a hour (in a healthy well tuned motor) over 175 F will dry it to under 800 ppm. Low enough to not be much of a factor. Motors with weak rings will take longer and the colder the air temperature the longer it takes.   On a cold motor there is also the condensation temperature. Blowby gases that contain moisture are subject to that cold cylinder wall, like sweat on a glass of ice tea. But also subject to the Law of Partial Pressures. Wear studies by GM and the DOD  indicate wear is a real issue below 85 F and a concern to 140 F but doesn't become a minimal factor until about 160 F. You know this intuitively when you see water vapor exit the exhaust pipe until the system gets above the dew point. It isn't magic, it's physics and it fascinates me. I know you didn't ask but....I over share sometimes. 😉    You keep the Camaro's high and tight.  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...