B20D9 Diagnostic Trouble Code

B20D9 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 B20D9 diagnostic trouble code may include:

Possible spark knock (detonation / pre-ignition)
Poor fuel economy
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
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data.

Process Tips

Diagnostic trouble code B20D9 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 B20D9.

Fortunately, B20D9 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B20D9 Trouble Code For Specific Cars

B20D9 Mercedes E 200 ABS Power Relay Coil Circuit Failure
B20D9 Alfa Romeo Giulia Additional Fan Relay Circuit Malfunction
B20D9 Salmson 2300 Illuminated Entry Input Open Circuit
B20D9 Peugeot 907 Electrodrive Fan 2 Operational Failure (Passenger Side)
B20D9 Toyota Caldina O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
B20D9 Fairthorpe Zeta Injector Circuit Malfunction - Cylinder 8
B20D9 Mitsubishi Montero Aux A/C Mode Position Reference Circuit Short to Battery