B0997 BMW Fault Code
Check B0997 OBD Fault Code ReasonBMW HO2S Sensor Circuit Malfunction (HO2S-11) During testing the HO2S Heaters are checked for opens/shorts and excessive current draw.
The BMW test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S. Water in harness connector. Open VPWR circuit. Open GND circuit. Low battery voltage. Corrosion or poor mating terminals and wiring Damaged HO2S heater. Damaged PCM.
B0997 Code Symptoms :
![See B0997 in engine](../obd/8.jpg)
The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. B0997 code had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditionning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.
Diagnosis And Repairing B0997
B0997 OBD2 specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-retarded, the engine light will be illluminated and the code will be set.
How to fix B0997 code ?
![See B0997 repair manual](../obd/1.jpg)
- Damaged camshaft position (CMP) sensor
- Faulty Intake Valve Timing Control Solenoid Valve
- Continuous oil flow to the VCT piston chamber
- Continuous oil flow to the VCT piston chamber
Gear changes are accomplished by a command from the BMW TCM to energize the clutch actuator to release the clutch; after which various actuators inside the transmission disengage the current gear, and depending on current operating conditions, engage the next higher or lower gear ratio. All of this happens much faster than a human driver could change gears, and in most applications, gear changes are as smooth and seamless as on any fully automatic transmission.