B3491 BMW Fault Code

Description:

Fuel Rail Pressure Sensor in Range But Low The comprehensive component monitor (CCM) monitors the FRP pressure for acceptable fuel pressure. The test fails when the fuel pressure falls below a calibrated value.

Low fuel pressure Damaged BMW FRP sensor Excessive resistance in circuit Low or no fuel A FRP PID value below 551 kpa (80 psi) indicates a failure Low or no fuel A FRP PID value greater than 896 kpa (130 psi) indicates a failure.

B3491 Code Symptoms :

There are currently two main types of cylinder deactivation used today, depending on the type of engine. B3491 code for the pushrod design which uses solenoids to alter the oil pressure delivered to the lifters. In their collapsed state, the lifters are unable to elevate their companion pushrods under the valve rocker arms, resulting in valves that cannot be actuated and remain closed.

Diagnosis And Repairing B3491

B3491 OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.

How to fix B3491 code ?

• 1Camshaft Position Sensor circuit poor electrical connection
• Faulty Variable Camshaft Timing (VCT) position solenoid
• Ignition coils circuit poor electrical connection
• Oil flow restriction in the oil passages or the variable camshaft timing (VCT) valve body

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code B3491, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code B3491 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.