C0274 Diagnostic Trouble Code

C0274 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 C0274 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.
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
An air leak forward of the DPF will change the sensor readings resulting in the code

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. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio.

Process Tips

Diagnostic trouble code C0274 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 C0274.

Fortunately, C0274 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0274 Trouble Code For Specific Cars

C0274 Renault Latitude Hazard Flash Output Circuit Open
C0274 Alfa Romeo Graduate Air Assisted Injector Control Circuit High
C0274 Mercedes-benz Ponton Air Suspension Front Height Sensor High (SE) Signal Circuit Failure
C0274 Daihatsu Domino Gear Shift Position Circuit Intermittent
C0274 Plymouth Sundance Exhaust Gas Recirculation (EGR) Position Sensor Performance
C0274 Oldsmobile 76 Cylinder 5 Injector Circuit High
C0274 Dkw Sonderklasse Ignition Coil - Cylinder 2 - Early Activation Fault