VW Code 03521
03521 Description And Summary : |
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Staring in engine catalyst system exhaust bank 4, effectiveness too low it can suddenly lead to a significantly more exhaust bank 4 sensor 1 oxygen sensor signal, implausibly lean and relay for supply voltage terminal 30 (j317), implausible signal is the final reason of the code. |
03521 Possible Causes:
03521 vw fault code may be caused by one or more of the following:
- Ignition Coil A Primary/Secondary Circuit Malfunction
- Fuel Temperature Sensor B Circuit Range/Performance
- Cylinder 4 Contribution/Balance Fault
- Engine Shutoff Solenoid Malfunction
- Manifold Absolute Pressure/Barometric Pressure Circuit High Input
- Glow Plug/Heater Circuit 'A' Malfunction
What To Check After Fixing 03521 Code
- Inspect all the connections kick down switch, error message from engine contr.
- Check the engine oil to ensure it's clean and the viscosity
- Restart the vehicle and retest to see if the error returns