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B12A6 BMW Fault Code

Check B12A6 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) B12A6 DTC is a check of the VCT unit.

B12A6 Code Symptoms :

See B12A6 in engine

When you turn on the ignition, the Service Engine Soon or Check Engine B12A6 light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the B12A6!

Diagnosis And Repairing B12A6

B12A6 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 B12A6 code ?

See B12A6 repair manual
  • Erratic camshaft position due to low oil pressure
  • Faulty Variable Camshaft Timing (VCT) position solenoid
  • Faulty spark plug (s)
  • Variable Camshaft Timing (VCT) position circuit poor electrical connection

To check for an open circuit, trace along the length of the transmission control circuit, checking for breaks in the wiring. Repair any broken wiring and make sure all connectors are fully seated and locked.

Pay close attention to connectors, looking for corrosion, bent or broken pins, or moisture in the connector. Repair any connector issues even if they are not specifically part of the transmission control circuit as they may serve a function in providing power to the transmission control circuit.

BMW Cars that meet B12A6 error