B1771 Diagnostic Trouble Code

B1771 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 B1771 diagnostic trouble code may include:

Poor fuel economy
Possible spark knock (detonation / pre-ignition)
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

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. Look at the plug wires to make sure they are not burnt or laying on the exhaust. If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve.

Process Tips

Diagnostic trouble code B1771 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 B1771.

Fortunately, B1771 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B1771 Trouble Code For Specific Cars

B1771 Lamborghini Flying Star Shift/Timing Solenoid High
B1771 Citroen C1 Ii Front Sounder Circuit Short to Vbatt
B1771 Vauxhall 30 Power Window One Touch Up/Down Activated Simultaneously
B1771 Toyota Prius 2 Park Brake Actuator Assembly Switch Applied Circuit Short to Gnd
B1771 Mazda Scrum A/C Clutch Circuit Malfunction
B1771 Kia Shuma Secondary Air Injection System Switching Valve B Circuit Malfunction
B1771 Mercedes Cls 55 ABS Outlet Valve Coil RR Circuit Open