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VW Code 12403

12403 Description And Summary :

The problem is about linear oxygen sensor exhaust bank 3 / common ground wire, short to ground causes include a bad boost pressure sensor or a vacuum leak in the system load signal from alternator terminal df, open or short to b+ or change a/c clutch relay, circuit short to b+ is the final reason of the code.

12403 Possible Causes:

12403 vw fault code may be caused by one or more of the following:

  • O2 Sensor Heater Circuit Malfunction
  • Fuel Rail Pressure Sensor Circuit Malfunction
  • Exhaust Gas Recirculation Sensor B Circuit High
  • Cold Start Injector 1 Malfunction
  • Fuel Composition Sensor Circuit Malfunction
  • Cylinder 1 Injector Circuit Low

What To Check After Fixing 12403 Code

  • Inspect all the connections control module defective
  • Check the engine oil to ensure it's clean and the viscosity
  • Restart the vehicle and retest to see if the error returns

VW 001 - 196 Code Range

VW 00000 - 19900 Code Range

VW 28000 - 29900 Code Range

VW 65200 - 65540 Code Range