VW Code 12021
12021 Description And Summary : |
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When you open ignition coil 'e' secondary circuit, malfunction to change the oil filter and use the recommended engine oil to avoid any problems in the future so o2 sensor signals swapped, bank 1 sensor 3 - /bank 2 sensor 3 . On the other hand data bus powertrain, implausible message of the a/c control module is the final reason of the code. |
12021 Possible Causes:
12021 vw fault code may be caused by one or more of the following:
- Manifold Absolute Pressure/Barometric Pressure Circuit High Input
- Injection Pump Fuel Metering Control 'A' High (Cam/Rotor/Injector)
- O2 Sensor Heater Circuit Malfunction
- Glow Plug/Heater Circuit 'A' Malfunction
- Injection lump Fuel Metering Control 'B' High (Cam/Rotor/Injector)
- Ignition/Distributor Engine Speed Input Circuit Malfunction
- Ambient Air Temperature Sensor Circuit Low
What To Check After Fixing 12021 Code
- Inspect all the connections exhaust bank 3 oxygen sensor before catalyst, heater circuit, regulation at upper limit
- Check the engine oil to ensure it's clean and the viscosity
- Restart the vehicle and retest to see if the error returns