C3868 Diagnostic Trouble Code

C3868 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 C3868 diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
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.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

Use the DVOM to test resistance and continuity on all system circuits if actuator and sensor resistance levels are in compliance with manufacturer's specifications. 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. 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 C3868 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 C3868.

Fortunately, C3868 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C3868 Trouble Code For Specific Cars

C3868 Volkswagen Passat B7 Right Rear Turn Lamp Circuit Short to Battery
C3868 Locomobile 30 Timing Reference High Resolution Signal A Intermittent/Erratic Pulses
C3868 Tvr Vixen Power Supply #1 Circuit Short to Ground
C3868 Renault Le Car Hazard Flash Output Circuit Short Battery
C3868 Mercedes Cls 350 ABS Outlet Valve Coil RF Circuit Short To Battery
C3868 Gaz M1 O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)
C3868 Tvr Tina Power Steering Pressure Sensor Circuit High Input