C2791 Diagnostic Trouble Code

C2791 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 C2791 diagnostic trouble code may include:

Blown fuse (if applicable)
Engine surge
Reduction in engine performance, especially at low RPM levels
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Dirty air cleaner element Damaged DPF

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector.

Process Tips

Diagnostic trouble code C2791 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 C2791.

Fortunately, C2791 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C2791 Trouble Code For Specific Cars

C2791 Allard M Air Bag Driver Circuit Short To Battery
C2791 Dodge Super 8 Ignition Tach Circuit Failure
C2791 Suzuki Maruti Mirror Driver Horizontal Switch Circuit Failure
C2791 Renault Megane 3 Heated Backlite Input Circuit Short To Ground
C2791 Lamborghini Lm Slip Solenoid System
C2791 Ghia 1500 Oil Change Reset Button Circuit Failure
C2791 Skoda 1200 Keep Alive Memory Test Failure