P0300 RAM 1500
Random/Multiple Cylinder Misfire Detected · Powertrain Code · High
What is P0300?
The ECM has detected misfires occurring in multiple or random cylinders. Common causes include worn spark plugs, faulty ignition coils, vacuum leaks, low fuel pressure, or a failing catalytic converter.
When the RAM 1500 triggers code P0300 (random/multiple cylinder misfire detected), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the RAM 1500.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your RAM 1500.
Common Causes on RAM 1500
- MDS (Multi-Displacement System) lifter failure on 5.7L HEMI V8 causing cylinder deactivation misfire
- Spark plug failure on 5.7L HEMI with 16-plug dual-ignition system
- Ignition coil degradation from heat soak on 5.7L HEMI exhaust-side coils
- Exhaust manifold bolt breakage causing exhaust leak and O2 misreading on HEMI
- Cam and lifter wear from oil starvation during MDS operation on high-mileage 5.7L
Symptoms
- Rough idle with noticeable engine vibration
- Engine shaking or stumbling under load
- Loss of power during acceleration
- Check engine light flashing intermittently
- Poor fuel economy
- Hesitation or stumble on acceleration
Notes for RAM 1500
The 5.7L HEMI uses 16 spark plugs (2 per cylinder); always replace all 16 as a set.