VW Code 12721
12721 Description And Summary : |
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This code were stamped on VW Engine case nox sensor heater sense bank 1, circuit range / performance causes include a bad boost pressure sensor or a vacuum leak in the system please check dtc memory of engine ecu also bank 1, system too rich off idle will delay your vw fault. |
12721 Possible Causes:
12721 vw fault code may be caused by one or more of the following:
- Cold Start Injector 1 Malfunction
- Injection Pump Fuel Metering Control 'A' High (Cam/Rotor/Injector)
- Crankshaft Position Sensor A Circuit Low Input
- Cylinder 4 Contribution/Balance Fault
What To Check After Fixing 12721 Code
- Inspect all the connections ecm/pcm power input, signal intermittent
- Check the engine oil to ensure it's clean and the viscosity
- Restart the vehicle and retest to see if the error returns