C0221
EPS Control Module Voltage Low
2001-2003 BMW 525i E39 2.5L I6 🇨🇦
Moderate SeverityChassis
Description
The EPS module supply voltage has dropped below the minimum operating threshold.
Symptoms
- EPS warning light
- Power steering assist reduced
- Assist cuts out during electrical load
- Steering heavy at idle with AC on
Common Causes
- Low battery voltage
- Weak alternator
- High resistance in EPS power supply wiring
- Corroded battery terminals
- Undersized wiring for EPS current demand
Diagnostic Steps
- Measure battery voltage at rest and running
- Test alternator output under load
- Check voltage at EPS module connector
- Inspect battery terminals and cable ends
- Test EPS power supply fuse and connections
Repair Notes
Repair charging system. Clean battery connections. Verify adequate wire gauge to EPS module.
Related Codes
Other Chassis Codes
- C0021LF Wheel Speed Sensor Range/Performance
- C0022RF Wheel Speed Sensor Range/Performance
- C0023LR Wheel Speed Sensor Range/Performance
- C0024RR Wheel Speed Sensor Range/Performance
- C0025LF Wheel Speed Sensor Circuit Intermittent
- C0026RF Wheel Speed Sensor Circuit Intermittent
- C0027LR Wheel Speed Sensor Circuit Intermittent
- C0028RR Wheel Speed Sensor Circuit Intermittent
- C0035Left Front Wheel Speed Sensor Circuit
- C0036Left Front Wheel Speed Signal Erratic
C0221 on Other Vehicles
Common Questions
What does code C0221 mean on a 2001-2003 BMW 525i E39?
C0221 stands for "EPS Control Module Voltage Low". The EPS module supply voltage has dropped below the minimum operating threshold.
What are the symptoms of C0221 on a BMW 525i E39?
Common symptoms of C0221 include: EPS warning light, Power steering assist reduced, Assist cuts out during electrical load, Steering heavy at idle with AC on.
What causes C0221 on a 2001-2003 BMW 525i E39?
Common causes of C0221 include: Low battery voltage, Weak alternator, High resistance in EPS power supply wiring, Corroded battery terminals, Undersized wiring for EPS current demand.