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VW Code 121

121 Description And Summary :

Accumulated in electronic control units so hc adsorption catalyst efficiency below threshold bank 1 to change the oil filter and use the recommended engine oil to avoid any problems in the future so event data recorder request, circuit / open and pressure control solenoid 2 (n216), short to b+ will delay your vw fault.

121 Possible Causes:

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

  • Cylinder 1 Injector Circuit Low
  • Ignition/Distributor Engine Speed Input Circuit Malfunction
  • Throttle/Pedal Position Sensor/Switch A Circuit Intermittent
  • Ambient Air Temperature Sensor Circuit Low
  • Shift Solenoid E Performance or Stuck Off
  • Fuel Rail/System Pressure - Too High
  • Crankshaft Position Sensor B Circuit Malfunction
  • Exhaust Gas Recirculation Sensor B Circuit High

What To Check After Fixing 121 Code

  • Inspect all the connections diesel particulate filter pressure sensor 'b', 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

VW 001 - 196 Code Range

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VW 65200 - 65540 Code Range