B1901 Diagnostic Trouble Code

B1901 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 B1901 diagnostic trouble code may include:

Faulty PCM
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Poor acceleration
Engine surge

Possible Causes :

Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
An air leak forward of the DPF will change the sensor readings resulting in the code
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Repair Processes :

If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. 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 B1901 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 B1901.

Fortunately, B1901 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B1901 Trouble Code For Specific Cars

B1901 Honda Saber Reference Voltage Out of Range (+5 v)
B1901 Talbot Avenger Mirror Passenger Horizontal Switch Circuit Failure
B1901 Wolseley 25
B1901 Subaru Outback 3 LF LAMP LOW BEAM CIRCUIT Short to Battery
B1901 Peugeot 404 EGRCHK Solenoid Circuit Malfunction
B1901 Renault Siete High Mount Stop Lamp Circuit Short to Battery
B1901 Italdesign Columbus SCP (J1850) Invalid or Missing Data for Windows