GM has issued a special coverage bulletin for certain units of the 2020 Chevy Silverado 1500 equipped with the 3.0L LM2 turbodiesel Duramax engine that may have been produced with a faulty glow plug for cylinder 2 of the engine.
If uncorrected, the faulty glow plug may fail in affected 2020 Chevy Silverado 1500 pickups, leading to two effects. A diagnostic trouble code will be set and the Check Engine light will illuminate.
As outlined by special coverage bulletin N232430460, if a potentially affected 2020 Chevy Silverado 1500 is showing the indications mentioned above that are related to a faulty glow plug, service personnel should verify that the condition described exists. This is carried out by checking the GM Global Warranty Management system to see if the truck is marked in the Applicable Warranties section.
This should be followed up by running diagnostics on the vehicle and checking the resulting diagnostic trouble code, if any. Repair consists of replacing the glow plug in cylinder 2 and the throttle body gasket. Total time with diagnosis is expected to be 1 to 1.7 hours.
Owners of 2020 Chevy Silverado 1500 trucks affected by the faulty glow plug issue are eligible “for reimbursement of their reasonable and customary expenses” related to the fix. This reimbursement is available as long as the truck is under warranty.
While the 2020 Chevy Silverado 1500 with the Duramax engine normally has a 5-year or 100,000-mile powertrain warranty (whichever comes first), the Special Coverage indicated by the bulletin begins on January 29th, 2024. It provides coverage for this issue, and this issue only, for a period of 15 years or 150,000 miles, whichever comes first.
As a reminder, the LM2 turbodiesel engine that may contain the faulty glow plug has been used in pickup trucks and SUVs, where its hefty low-end torque adds to towing capability. The LM2’s output  is rated at 277 horsepower at 3,750 rpm and 460 pound-feet of torque at 1,500 rpm in the 2019 through 2021 model-year Chevy Silverado 1500, GMC Sierra 1500, Chevy Tahoe, Chevy Suburban, GMC Yukon, and Cadillac Escalade vehicles, where it is always paired with the GM 10-speed automatic transmission.
Chevy Silverado 1500 production currently takes place at the GM Silao plant in Mexico, GM Fort Wayne plant in Indiana, and GM Oshawa plant in Canada.
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Comments
I don’t understand how only one glow plug is effected and how it’s always the number 2 cylinder? I would have thought that all 6 glow plugs would be the same. Maybe not, what makes number 2 special?
It’s a manifold or valve cover issue (can’t remember which from a few videos I’ve seen). A short internal baffle allowed oil to get past the barrier bypass and could foul #2. They have redesigned that part for the LZ0. It seems many have had this issue. A secondary result is that since the glow plug gets fouled, it makes the truck eat more DEF too. A secondary tell that there is an issue with #2.
Hope this helps. Check out YouTube on the videos regarding this.
Thanks
My 2020 check engine light came on. Checked with code reader = P1339. Then code P04D2 came on 4 days later. There are tech bulletins for both codes. The P1339 seems to be glow plug 2 and the intake seem to be the cause (covered under a special warranty) and the other is the EGR temperature sensor. I’ll be making an appointment with the dealer. There are only 33,000 miles on the truck.