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B1127 BMW Fault Code

Check B1127 OBD Fault Code Reason
Description:

Variable Cam Timing Over-advanced (Bank 1) The comprehensive component monitor (CCM) monitors the VCT position for an over-advanced camshaft timing.
The test fails when the camshaft timing exceeds a maximum calibrated value or remains in an advanced position.

BMW cam timing improperly set No oil flow to the VCT piston chamber Low oil pressure VCT solenoid valve stuck closed Camshaft advance mechanism binding (VCT unit) B1127 DTC is a check of the VCT unit.

B1127 Code Symptoms :

See B1127 in engine

The B1127 Check Engine lamp is perhaps the most troubling of lights because it could mean so many different things, from you didn't screw the gas cap on tightly enough to look out for pistons flying through the hood and into the stratosphere. The easiest way to find out what this light is telling you is to hook your vehicle up to a scan tool. B1127 diagnostic tool looks a little like an oversized calculator and plugs into a communication port inside the car. After you instruct it to perform the scan, it speaks with your car's computers to find out exactly what's prompting the light to turn on.

Diagnosis And Repairing B1127

Parts or components should not be replaced with reference to only a B1127 DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.

How to fix B1127 code ?

  • Erratic camshaft position due to low oil pressure
  • Faulty Crankshaft Position Sensor (POS)
  • Camshaft advance mechanism binding (VCT unit)
  • Faulty Air Flow Meter

On some transmissions, such as automated manual transmissions or automatic transmissions with manual mode, the GSP switch lets the TCM know whether or not the driver has selected automatic or manual function.

On manual transmissions, the GSP switch informs the TCM which gear the driver is selecting, and may function as a neutral safety switch, depending on system design. The TCM also uses the gate select position switch to monitor transmission operation. For example, if the driver selects manual mode and selects 3rd gear on an automatic transmission, the TCM may monitor speed sensors to detect clutch and brake slippage.

BMW Cars that meet B1127 error