Ram check engine codes

Overview

Ram trucks use Hemi V8 and Pentastar V6 engines. Misfires related to cylinder deactivation, EVAP leak detection faults, and thermostat codes are common.

Codes notably common on Ram

• P0300 Random or Multiple Cylinder Misfire Detected · Ram notes
• P0456 Evaporative Emission System Very Small Leak Detected
• P0455 Evaporative Emission System Large Leak Detected
• P0128 Coolant Thermostat (Coolant Temperature Below Regulating Temperature)
• P0420 Catalyst System Efficiency Below Threshold (Bank 1)

Ram specific notes

• 5.7 liter Hemi lifter and camshaft wear is frequently reported by owners and shops; we have not found a manufacturer bulletin confirming a defect.
• Diesel Ram trucks use different emissions systems and codes than those covered here.
• Chrysler guidance for EVAP codes calls for a smoke test before replacing the ESIM.

Owner's manuals

Official Ram owner's manual / owner portal (manufacturer site; we do not host copies).

Recall lookup

Check open Ram recalls with your VIN at the NHTSA recall lookup.

Sources

• https://dot.report/bulletins/10119601
• https://www.nhtsa.gov/recalls

Sources checked October 2026. Bulletins apply only to the models and years they list.

All other codes

These work the same on Ram as on any vehicle:

P0430 P0301 P0302 P0303 P0304 P0171 P0174 P0440 P0442 P0135 P0141 P0101 P0299 P2135 P0401