What does this code mean?
P0300 indicates random or multiple-cylinder misfire. P0301–P0308 identify the numbered cylinder. Ignition, fuel delivery, compression, air leaks or mechanical timing can cause misfire. Use misfire counters, freeze-frame data and appropriate tests to narrow the cause. A flashing malfunction light can signal a misfire that may damage the catalyst.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
9Original wording in English
BUICK, CADILLAC, CHEVROLET, GMC, HUMMER, PONTIAC, SAAB
Reported code forms P0300
This Preliminary Information communication provides information to the technician about vehicles that have a Service Engine Soon Malfunction Indicator Lamp on, engine misfire, and/or engine noise. Technician may find…
CHEVROLET, GMC
Reported code forms P0300
POOR ENGINE PERFORMANCE - MISFIRE, ROUGH IDLE, STALLS, ENGINE CRANKS BUT DOES NOT RUN, SERVICE ENGINE SOON/CHECK ENGINE LIGHT ILLUMINATED, DIAGNOSTIC TROUBLE CODE (DTC) P0300 SET. *TT
CHEVROLET, GMC, OLDSMOBILE
Reported code forms P0300
POOR ENGINE PERFORMANCE - MISFIRE, ROUGH IDLE, SERVICE ENGINE SOON/CHECK ENGINE LIGHT ILLUMINATED, DIAGNOSTIC TROUBLE CODE (DTC) P0300 SET. *TT
CHEVROLET, GMC, OLDSMOBILE
Reported code forms P0300
4.3L L35 ENGINE-DIAGNOSTIC TROUBLE CODE P0300 BUT NO MISFIRE CAN FELT. *MJ
CHEVROLET, GMC
Reported code forms P0300
MALFUNCTION INDICATOR LAMP ON WITH A P0300 SET AND A MISFIRE. VARIOUS MODELS INCLUDING 1996 - 1999 P32 MODELS. SIT BULLETIN 1416475. *TT
CHEVROLET, GMC
Reported code forms P0300
MALFUNCTION INDICATOR LAMP ON WITH A P0300 SET AND A MISFIRE. VARIOUS MODELS INCLUDING THE 1996-1999 P32 AND THE 1996-2002 GMC C/K TRUCK. *TT
Check vehicle applicability
1A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
| Make | Model | Model year |
|---|---|---|
| GMC | SIERRA | 2001 |
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 01 13 14 / 2033805 · Engine, Misfire Diagnostic Aid ↗
Volkswagen Group of America · PDF page(s) 1, 2 ·
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 9, 10 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.