C2491 Diagnostic Trouble Code

C2491 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a C2491 diagnostic trouble code may include:

Corroded or damaged connector
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Lack of power
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data.

Process Tips

Diagnostic trouble code C2491 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C2491.

Fortunately, C2491 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C2491 Trouble Code For Specific Cars

C2491 Bmw X5 Column Reach Feedback Potentiometer Circuit Short to Battery
C2491 Rover Land Rover Ignition Coil I Primary/Secondary Circuit Malfunction
C2491 Lancia Medusa Split Air #1 Circuit Malfunction
C2491 Saturn Lw Immobilizer to PCM Signal Error
C2491 Tvr M Power Door Unlock Circuit Open
C2491 Mercedes C 200 ABS Hydraulic Pump Motor Circuit Short To Ground
C2491 Volvo S80 Ii SCP (J1850) Invalid or Missing Data for Experimental #3