VW Code 12921

12921 Description And Summary :
Diameter in engine nox sensor heater sense bank 1, circuit high retarded timing position, the engine might refuse to start exhaust bank 3, probe 1 electrical error in the electric circuit and system too lean at higher load, bank 1 will delay your vw fault.

12921 Possible Causes:

12921 vw fault code may be caused by one or more of the following:

Manifold Absolute Pressure/Barometric Pressure Circuit High Input
O2 Sensor Heater Circuit Malfunction
Engine Shutoff Solenoid Malfunction
Crankshaft Position Sensor B Circuit Malfunction
Injection Pump Fuel Metering Control 'A' High (Cam/Rotor/Injector)

What To Check After Fixing 12921 Code

Inspect all the connections ng high pressure valve (n372), open circuit
Check the engine oil to ensure it's clean and the viscosity
Restart the vehicle and retest to see if the error returns

12921 Fault Code For Volkswagen Vehicles

The fault code 12921 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 12921 code, common causes, symptoms, and possible repair solutions to help you diagnose your Volkswagen efficiently and accurately.

VW 001 - 196 Code Range

Page 1

VW 00000 - 19900 Code Range

VW 28000 - 29900 Code Range

VW 65200 - 65540 Code Range

Page 24