B0855 Diagnostic Trouble Code

B0855 is a kind of OBD-II Diagnostic B-Body 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 B0855 diagnostic trouble code may include:

Misfire
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly

Possible Causes :

A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Faulty IMRC actuator/sensor
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Look at the plug wires to make sure they are not burnt or laying on the exhaust. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code B0855 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 B0855.

Fortunately, B0855 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B0855 Trouble Code For Specific Cars

B0855 Ford Galaxie Mirror Driver Horizontal Switch Circuit Open
B0855 Fiat 850 Lamp Dome Input Circuit Short To Ground
B0855 Matra M530 Transmission Neutral Safety Switch Open Circuit
B0855 Porsche Gt2 Fuel Pump Resistor Switch Circuit Malfunction
B0855 Kissel 6 Servo Motor Potentiometer Airintake Left Circuit Short To Ground
B0855 Talbot 25 Mirror Passenger Horizontal Feedback Potentiometer Circuit Failure
B0855 Humber 16 Right Rear Backup Lamp Circuit Failure