C279D Diagnostic Trouble Code

C279D 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 C279D diagnostic trouble code may include:

Cherry red hot catalytic converter
Poor acceleration
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Reduction in engine performance, especially at low RPM levels

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.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. 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. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code C279D 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 C279D.

Fortunately, C279D is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C279D Trouble Code For Specific Cars

C279D Chevrolet Grand Blazer Dual Alternator Lower Circuit Malfunction/ Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent Low Voltage
C279D Volkswagen Sharan SCP (J1850) Communication Bus Fault
C279D Datsun Deluxe HO2S Heater Control Circuit (Bank 1 Sensor 3)
C279D Lti Tx Traction Control Valve LF Circuit Failure
C279D Gaz 69am O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
C279D Fiat V8 Left Lamp Outage Signal Circuit Short to Ground
C279D Buick Xp-300 Damper Low Side Rear Circuit Failure