GM V8 cold P050D/P0300: diagnose before opening the engine. See the manufacturer document, vehicle conditions, exclusions and questions for a qualified shop before assuming a repair.
This is a research summary of a manufacturer communication, not a diagnosis for your car, a DIY repair procedure or confirmation of warranty or recall eligibility. No qualified technician has approved a repair for your individual vehicle here.
This historical communication is conditional. The current revision, VIN/build eligibility, measured diagnosis and any warranty or recall decision are not established here. Ask the manufacturer or a qualified shop to check the complete current document.
Read the General Motors original: V8 cold misfire: coolant-entry verification · Check open recalls by VIN at NHTSA Source date: 2024-03; research checked: 2026-11-01.
What prompted this manufacturer document
- Cold-start misfire
- Rough running when warm, sometimes without codes
- The bulletin requires normal ignition/mechanical/injector diagnosis before concluding coolant intrusion; premature engine disassembly has produced no-fault-found cases.
Which vehicle conditions must be checked
Each row below retains its own conditions. Do not combine engines, years or models across rows to create new applications. A listed model is not proof that a particular VIN is affected.
- Cadillac CTS · 2016, 2017, 2018, 2019 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Cadillac Escalade · 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Camaro · 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Corvette · 2016, 2017, 2018, 2019 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Silverado · 2014, 2015, 2016, 2017, 2018 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Silverado 1500 · 2019 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Silverado 1500 LTD · 2022 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Silverado 1500 New · 2022 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Silverado LD · 2019 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Silverado 1500 · 2020, 2021, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Suburban · 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- Chevrolet Tahoe · 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Sierra · 2014, 2015, 2016, 2017, 2018 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Sierra 1500 · 2019 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Sierra 1500 Limited · 2022 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Sierra 1500 New · 2022 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Sierra Limited · 2019 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Sierra 1500 · 2020, 2021, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
- GMC Yukon models · 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024 · RPO scope grouped by source: L82,L83,L86,L84,L87,LT1,LT4,LT5; verify actual vehicle engine; gasoline
Codes recorded in this document
A root listed only as an appearance has no separately verified meaning here. Preserve every suffix and module name; a shared root does not transfer a repair branch to another vehicle.
| Root | Raw form | Meaning in this source, if established |
|---|---|---|
| P050D | P050D | Cold-start rough-idle detection in this diagnostic context |
| P0300 | P0300 | Appears in the document; individual meaning not verified |
What an owner can record safely
- Cold versus warm symptom pattern
- Coolant-level trend
- Prior injector flow-class/part records
Editorial safety boundary for this system
Rough running, persistent white exhaust with coolant loss, significant noise or overheating warrants stopping and professional evaluation.
- Use current model-specific service information, calibrated equipment and a qualified technician for the selected diagnostic branch.
- Avoid repeated cranking after an engine stops or mechanical failure is suspected.
This is a conservative editorial policy, not a manufacturer safe-to-drive decision for a specific vehicle.
What the source does not prove
- Do not mix injector flow classes on the RPOs identified by GM or dismantle the engine before the diagnostic tree.
- A code or message alone does not establish a failed part, a safe-to-drive decision or an approved repair for this VIN.
- A service bulletin is not automatically a recall or free warranty repair. Confirm current eligibility directly.
Questions for the repair shop
- Which current manufacturer procedure, VIN/RPO/build gate and test result determine the diagnostic branch?
- Does a later revision or a current recall change the source's original advice?
- What measurement or inspection confirms the cause, and how will the repair be verified?
Open source-review issue
- Q3-10: Shared engine/RPO columns cover several model rows. Never produce a Cartesian product of every engine and every year/model. Verify VIN/RPO pairing first.
The uncertain field is not used here to claim a current fitment, repair or market-wide failure.
Read the original record
The linked communication may be revised after the research date. Compare its document number, exact vehicle table, diagnostic preconditions and exclusions with a qualified technician. This page paraphrases selected facts and does not reproduce the manufacturer procedure.
Sources and scope
- General Motors — V8 cold misfire: coolant-entry verification (20-NA-166) Document: 2024-03 · Research checked: 2026-11-01
Research snapshot: 2026-11-01. Source documents may have newer revisions. Verify current instructions and VIN eligibility with the manufacturer.