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C3771 BMW Fault Code

Check C3771 OBD Fault Code Reason
Description:

Brake Switch Circuit Input Malfunction Indicates PCM did not receive a brake pedal position (BPP) input. Open or short in BPP circuit Open or short in stoplamp circuits damaged PCM Malfunction in module(s) connected to BPP circuit.

(Rear Electronic Module [REM] Windstar and LS6/LS8 or Lighting Control Module (LCM) Continental and Town Car. Damaged brake switch Misadjusted brake switch Check for proper function of stoplamps.

C3771 Code Symptoms :

See C3771 in engine

There are currently two main types of cylinder deactivation used today, depending on the type of engine. C3771 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 C3771

C3771 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 C3771 code ?

See C3771 repair manual
  • Damaged ECM
  • Camshaft advance mechanism binding (VCT unit)
  • Fuel injector leaks
  • Open VPWR circuit

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code C3771, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code C3771 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.

BMW Cars that meet C3771 error