VANOS Supply Voltage Low
1997-2003 BMW 540i E39 4.4L V8 🇨🇦
Description
The DME detected that the supply voltage to the VANOS (Variable Nockenwellen Steuerung) solenoid system is below the minimum threshold. VANOS controls variable valve timing on BMW engines and requires stable voltage for precise operation.
Symptoms
- Check Engine Light
- Rough idle
- Loss of power at low RPM
- VANOS rattle on startup
- Poor fuel economy
Common Causes
- Low battery voltage
- Faulty voltage regulator
- High-resistance connection in VANOS power supply
- Corroded VANOS solenoid connector
- Failing alternator
Diagnostic Steps
- Test battery voltage under load
- Check alternator output
- Measure voltage at VANOS solenoid connector
- Inspect wiring for high resistance
- Check ground connections
Repair Notes
Repair the low-voltage condition by addressing the battery, alternator, or wiring fault.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1447 on Other Vehicles
Common Questions
What does code P1447 mean on a 1997-2003 BMW 540i E39?
P1447 stands for "VANOS Supply Voltage Low". The DME detected that the supply voltage to the VANOS (Variable Nockenwellen Steuerung) solenoid system is below the minimum threshold. VANOS controls variable valve timing on BMW engines and requires stable voltage for precise operation.
What are the symptoms of P1447 on a BMW 540i E39?
Common symptoms of P1447 include: Check Engine Light, Rough idle, Loss of power at low RPM, VANOS rattle on startup, Poor fuel economy.
What causes P1447 on a 1997-2003 BMW 540i E39?
Common causes of P1447 include: Low battery voltage, Faulty voltage regulator, High-resistance connection in VANOS power supply, Corroded VANOS solenoid connector, Failing alternator.