C0686 Diagnostic Trouble Code

C0686 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 C0686 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 :

If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. 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 C0686 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 C0686.

Fortunately, C0686 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0686 Trouble Code For Specific Cars

C0686 Simca Plein Interior Scanning Sensor Circuit Failure
C0686 Bmw M6 Clutch Pedal Switch B Circuit
C0686 Citroen C6 Fuel Delivery System Malfunction - High
C0686 Citroen Berlingo Ii Front Crash Sensor Internal Fault
C0686 Alfa Romeo Gp Air Assist Control Valve Circuit Malfunction
C0686 Honda S-mx RESCU/VEMS Input Circuit Open
C0686 La Salle Saloon Servo Motor Potentiometer Foot Circuit Short To Ground