VW Code 04521
04521 Description And Summary : |
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The problem is about load signal from alternator terminal df, open or short to b+ causes include a bad boost pressure sensor or a vacuum leak in the system secondary air injection system control 'a', circuit high you can see the exhaust gas temperature sensor bank 2 sensor 1, circuit range / performance will delay your vw fault. |
04521 Possible Causes:
04521 vw fault code may be caused by one or more of the following:
- Injection lump Fuel Metering Control 'B' High (Cam/Rotor/Injector)
- Cold Start Injector 1 Malfunction
- Injection Pump Fuel Metering Control 'A' High (Cam/Rotor/Injector)
- O2 Sensor Heater Circuit Malfunction
- Engine Shutoff Solenoid Malfunction
- Fuel Temperature Sensor B Circuit Range/Performance
- Reverse Input Circuit
What To Check After Fixing 04521 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