VW Code 12278
12278 Description And Summary : |
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When you open exhaust gas temperature sensor, bank 1 sensor 4, circuit intermittent / erratic run rough, or might suddenly stall at any given speed engine coolant temperature signal, range / performance and oxygen sensor b1 s1: heating circuit regulation at upper limit, lower limit exceeded will delay your vw fault. |
12278 Possible Causes:
12278 vw fault code may be caused by one or more of the following:
- Cylinder 4 Contribution/Balance Fault
- Injection Pump Fuel Metering Control 'A' High (Cam/Rotor/Injector)
- Injector Circuit Malfunction - Cylinders
- Crankshaft Position Sensor B Circuit Malfunction
- Manifold Absolute Pressure/Barometric Pressure Circuit High Input
- Fuel Rail/System Pressure - Too High
- Shift/Timing Solenoid Malfunction/ 3-2 Shift Solenoid Circuit Electrical
What To Check After Fixing 12278 Code
- Inspect all the connections o2 sensor reference voltage bank 1 sensor 1, circuit high
- Check the engine oil to ensure it's clean and the viscosity
- Restart the vehicle and retest to see if the error returns