B1946 Diagnostic Trouble Code

B1946 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 B1946 diagnostic trouble code may include:

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
Faulty or damaged wiring
Hesitation upon acceleration
Diminished fuel efficiency

Possible Causes :

The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Defective ECU strategies or components will prevent proper regeneration
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

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. Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors.

Process Tips

Diagnostic trouble code B1946 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 B1946.

Fortunately, B1946 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B1946 Trouble Code For Specific Cars

B1946 Singer 2-litre Internal Control Module ROM Error (Module Identification Defined by SAE J1979)
B1946 Caterham R300 Door Ajar RR Circuit Short To Ground
B1946 Maserati 8cl Transmission Fluid Pressure Sensor/Switch B Circuit High
B1946 Mercedes-benz Sprinter Air Suspension Gate Solenoid Output Circuit Failure
B1946 Skoda L Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)
B1946 Hyundai Xg
B1946 Daewoo Vada Gear Control Malfunction