Chrysler check engine codes

Overview

Chrysler models share Stellantis engines with Dodge and Jeep. EVAP leak detection modules and thermostats are frequently discussed causes.

Codes notably common on Chrysler

• 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)

Chrysler specific notes

• Many Chrysler vehicles use an Evaporative System Integrity Monitor (ESIM). Chrysler guidance calls for checking the cap and hoses and doing a smoke test and software check before replacing the ESIM or canister, so do not assume the ESIM is bad.

Owner's manuals

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

Recall lookup

Check open Chrysler 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 Chrysler as on any vehicle:

P0430 P0300 P0301 P0302 P0303 P0304 P0171 P0174 P0440 P0442 P0135 P0141 P0101 P0299 P2135 P0401