P312B BMW Fault Code
Check P312B 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.
P312B Code Symptoms :
If your vehicle failed a P312B test and the P312B Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses P312B a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look : Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression.
Diagnosis And Repairing P312B
Parts or components should not be replaced with reference to only a P312B DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.
How to fix P312B code ?
- Damaged camshaft position (CMP) sensor
- 1Camshaft Position Sensor circuit poor electrical connection
- Incorrect fuel pressure
- Faulty TCM or TCM programming
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.
