C0221moderate severityChassis
EPS Control Module Voltage Low
on 2016 Lincoln MKX 3.7L V6 · AWD
What this code means
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.
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Bluetooth code reader (~$25)
Veepeak OBDCheck BLE →
Pairs with your phone — reads and clears codes, live data.
Serious DIY (~$100)
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
Shop-grade tablet (~$300+)
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
As an Amazon Associate, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Chassis codes on this vehicle
C0021
LF Wheel Speed Sensor Range/Performance
C0021
LF Wheel Speed Sensor Range/Performance
C0022
RF Wheel Speed Sensor Range/Performance
C0022
RF Wheel Speed Sensor Range/Performance
C0023
LR Wheel Speed Sensor Range/Performance
C0023
LR Wheel Speed Sensor Range/Performance
C0024
RR Wheel Speed Sensor Range/Performance
C0024
RR Wheel Speed Sensor Range/Performance
C0025
LF Wheel Speed Sensor Circuit Intermittent
C0025
LF Wheel Speed Sensor Circuit Intermittent