B1C71 Diagnostic Trouble Code

B1C71 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 B1C71 diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
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 :

Defective ECU strategies or components will prevent proper regeneration
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.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

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. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors.

Process Tips

Diagnostic trouble code B1C71 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 B1C71.

Fortunately, B1C71 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B1C71 Trouble Code For Specific Cars

B1C71 Audi Rs2 ASM Control Circuit Range/Performance
B1C71 Toyota Coaster O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
B1C71 Mazda Carol Transmission Transfer Case Differential Lock-Up Solenoid Open Circuit
B1C71 Mazda Atenza Transmission Transfer Case Contact Plate Power Short To Battery
B1C71 Jensen Sv8 Seat Front Up/Down Potentiometer Feedback Circuit Failure
B1C71 Matra-simca Bagheera Transmission Neutral Safety Switch Short Circuit To Battery
B1C71 Morris Marina Brake Switch Circuit Failure