Why the Check Engine Light Comes On in a Dodge Ram
The Ram’s PCM illuminates the MIL when it detects faults in ignition, fuel, emission or transmission systems. Typical triggers include:
- Misfires from failing coils or plugs.
- EVAP leaks from loose gas caps or cracked hoses.
- O2 sensor or catalyst issues after extended misfire driving.
- Thermostat or coolant temperature faults (P0128).
- Transmission adaptives or solenoid faults (P0700 and related codes).
Use a scan tool to read codes, fix the underlying problem, and clear the light. If the MIL flashes, treat it as an emergency—reduce throttle immediately and repair the misfire to protect the catalyst.
Consult the full Ram check engine light guide for detailed diagnostics.