C1101 on Hyundai: How to Diagnose & Fix
ABS System Battery/Charging Voltage High
1 Hyundai model · 1 documented issue · 1 critical
C1101 on Hyundai by model: symptoms, diagnosis and fix
The Motor-Driven Power Steering (MDPS) unit can fail, illuminating the EPS warning light and causing sudden loss of power assist or a steering wheel that becomes very tight/hard to turn - sometimes during low-speed maneuvers (parking, tight turns) and sometimes at highway speed (~35 mph). Owners report having to stop, shift to park, and restart the engine to clear the light, and that the wheel can briefly 'lock' or require very high effort. Root causes traced to the MDPS module/motor, wiring-harness connections, or the steering-angle sensor. Hyundai issued a warranty extension covering the MDPS/EPS unit for EPS-warning-light illumination on 2016-2017 model-year vehicles from 5yr/60,000 mi to 15yr/150,000 mi.
Common Symptoms
- EPS / MDPS warning light on
- Sudden loss of power steering assist
- Steering wheel very hard to turn or briefly locked
- Loss of assist during tight low-speed turns or at ~35 mph
- Light clears only after restarting the engine
How to Fix
Scan for MDPS-related codes and inspect the wiring harness/connectors and steering-angle sensor before condemning the unit; repairing a connection sometimes resolves it. A failed MDPS module is replaced. For 2016-2017 vehicles the MDPS/EPS unit is covered under the extended warranty (15yr/150,000 mi) when the EPS light illuminates - have it documented and repaired under that coverage.
Sources for this issue (3)
C1101 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C1101 mean on a Hyundai?
C1101 stands for "ABS System Battery/Charging Voltage High." This is a chassis (ABS/stability control) code indicating the anti-lock brake or electronic stability module detected battery/charging system voltage outside its acceptable range, typically too high. The ABS module monitors supply voltage because it needs stable power to operate the pump and solenoids safely; out-of-range voltage can make it disable ABS/traction features as a precaution. On most makes this points to a charging-system problem rather than a brake fault, though the exact wording can vary by manufacturer. On Hyundai it is documented across 1 model: Sonata.
What are the most common causes of C1101?
The most common causes of C1101 are: Overcharging alternator / faulty voltage regulator, Weak, failing, or corroded battery, Loose or corroded battery terminals and ground straps, Poor connections at the ABS module power feed, Damaged charging-system wiring, Faulty ABS/EBCM module (less common). The specific cause varies by vehicle.
How much does it cost to fix C1101 on a Hyundai?
Repair costs vary widely with the root cause and Hyundai model; each issue on this page carries its own estimate where one is published.
Looking for C1101 on a different make?
View C1101 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.