dtc,description,severity,action,clock,notes
P0300,Random misfire,High,Pull vehicle; inspect coils/plugs/injectors,24h,Protect cat & engine
P0420,Catalyst efficiency low,Medium,Schedule inspection; check O2 & leaks,7d,Often post-misfire
P0117,ECT low input,High,Check sensor/wiring; verify coolant,24h,Could mask overheat
P0118,ECT high input,High,Stop & diagnose cooling system,Immediate,Overheat risk
P0128,Coolant thermostat,Medium,Replace thermostat; check coolant,7d,Affects fuel use
P0520,Oil pressure sensor,High,Verify true pressure; check pump,Immediate,If real: engine risk
P0401,EGR insufficient flow,Medium,Clean/replace EGR; check DP,7d,Driveability/fuel
P2002,DPF efficiency,High,Regeneration/inspect leaks,48h,Monitor soot/temps
U0100,Lost comm with ECM,High,Electrical/bus diag,24h,Intermittent harness