VW Code 12120

12120 Description And Summary :
The problem is about exhaust bank 4 mixture adaptation range 3, rich limit exceeded It could be due to limited air getting through your air intake supply voltage for fuel injector group b, short to ground . On the other hand fuel cap sensor / switch, circuit high is the final reason of the code.

12120 Possible Causes:

12120 vw fault code may be caused by one or more of the following:

Cylinder 10 Contribution/balance Fault
Reverse Input Circuit
Ignition/Distributor Engine Speed Input Circuit Malfunction
Cylinder 4 Contribution/Balance Fault
Shift/Timing Solenoid Malfunction/ 3-2 Shift Solenoid Circuit Electrical
Crankshaft Position Sensor A Circuit Malfunction
Cylinder 1 Injector Circuit Low

What To Check After Fixing 12120 Code

Inspect all the connections o2 sensor signal bank 1 sensor 2, biased / stuck rich
Check the engine oil to ensure it's clean and the viscosity
Restart the vehicle and retest to see if the error returns

12120 Fault Code For Volkswagen Vehicles

The fault code 12120 is associated with Volkswagen (VW) vehicles and indicates a specific issue detected by the onboard diagnostics (OBD) system. Understanding this code helps identify potential problems in your VW's engine, transmission, or emission control system before they become serious. This page provides a detailed explanation of the 12120 code, common causes, symptoms, and possible repair solutions to help you diagnose your Volkswagen efficiently and accurately.

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