Check Engine Light On But No Codes
Check engine light on but no codes? Learn why scanner mode, pending codes, readiness, permanent codes, or scanner limits may be the issue.
Michael Hayes
OBD2 Drive Cycle Explained
OBD2 drive cycle explained: how drive cycles complete readiness monitors, confirm repairs, and help permanent codes clear after emissions repairs.
How to Clear OBD2 Codes Without Losing Data
How to clear OBD2 codes safely: save codes, freeze frame, readiness, and permanent-code data before using the clear-code function.
Car Shaking and Check Engine Light: What It Means
Car shaking with check engine light on? Learn why misfire is likely, when to stop driving, what scanner data to save, and what to check first.
Check Engine Light Flashing: What to Do First
Check engine light flashing? Learn why active misfire is urgent, when to stop driving, what scanner data to save, and what to check first.
OBD2 Port Not Working: Fuse and Power Checks
OBD2 port not working? Check ignition position, fuse, pin 16 power, ground pins, connector damage, scanner setup, and communication problems.
OBD2 Permanent Codes Explained
OBD2 permanent codes explained: why they stay after repair, why scanners cannot force-clear them, and how readiness monitors clear them.
OBD2 Pending Codes Explained
OBD2 pending codes explained: what pending means, why codes appear, when to worry, and why you should save data before clearing codes.
Bidirectional Control on OBD2 Scanners Explained
Bidirectional control on OBD2 scanners explained: active tests, actuator commands, service functions, safety warnings, vehicle coverage, and buying advice.
OBD2 Live Data Normal Values
OBD2 live data normal values for fuel trims, coolant temperature, MAF, O2 sensors, RPM, load, readiness, and scanner diagnosis.