C1101: How to Diagnose & Fix — ABS System Battery/Charging Voltage High
3 vehicles · 2 makes · $80-$1,500 repair
How to diagnose and fix C1101: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Hyundai Sonata · 2015–2017
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)
Nissan Altima · 2002–2012
A recurring higher-mileage Altima problem is front wheel bearing wear, often first noticed as a humming or growling noise that increases with road speed. As the bearing deteriorates, owners may feel vibration, looseness, or see ABS warnings if the integrated wheel speed signal becomes erratic. This is widely reported in repair databases and owner forums, especially on cars driven on rough roads.
Common Symptoms
- humming noise from front wheel
- growling that changes with speed
- vibration
- ABS light
- wheel play
- noise changes when turning
How to Fix
Diagnosis includes road testing for load-sensitive humming, checking for play at the wheel, and using a chassis ear or scan tool to compare wheel speed signals if ABS lights are present. Repair typically requires replacing the affected hub/bearing assembly or pressing in a new bearing depending on model year and setup. An alignment check is wise if other front-end wear is present.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan front wheel bearing 40210-3Z000
Confirm axle-nut and seal requirements by VIN.
- Genuine Nissan QR25DE front hub 40202-9HC1A
2007-2012 Nissan Altima 2.5L QR25DE for this card, within the page's broader 2007-2013 fitment; left or right front. Not for VQ35DE.
- Genuine Nissan VQ35DE front hub 40202-3JA1A
2007-2012 Altima 3.5L VQ35DE for this card, left or right front; verify VIN/current supersession.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipDo not assume tire noise; many owners chased alignment and tire issues before confirming the bearing by loading the car side-to-side during a road test.
- TipIf an ABS light appears with bearing noise, inspect the hub tone ring/sensor signal before replacing separate ABS components.
Nissan Frontier · 2005–2024
The Frontier's wheel speed sensors sit exposed at the hubs and fail from corrosion, road salt and debris damage, and because the same signal feeds the anti-lock brakes, the Vehicle Dynamic Control stability system and the traction control, one dead sensor lights the whole cluster: ABS, VDC OFF and SLIP illuminate together, usually accompanied by the BRAKE lamp. Owners frequently misread this as an ABS pump or master cylinder fault. A documented secondary consequence is that the loss of a wheel speed signal can also prevent the truck from shifting into four-wheel drive, since the transfer case control logic uses those signals. The wiring and connector at the sensor are as often at fault as the sensor element itself, since the harness runs through the wheel arch and chafes or corrodes at the connector. Normal braking is retained but ABS and stability control are disabled until the fault is cleared.
Common Symptoms
- ABS, VDC OFF and SLIP lights on together
- Brake warning light on with normal pedal feel
- ABS does not activate in a hard stop
- Speedometer drops out intermittently
- 4WD refuses to engage
How to Fix
Scan ABS codes and inspect the harness, connector and tone ring first. The linked sensors are rear-corner branches only; do not use them for a front-corner code.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan rear ABS sensor, driver side, C200 branch, 47901-9CA5A$269
Confirm VIN, corner and axle before ordering.
- Genuine Nissan rear ABS sensor, passenger side, C200 branch, 47900-9CA5A$269
Confirm VIN, corner and axle before ordering.
- Genuine Nissan rear ABS sensor, driver side, M226 branch, 47901-9CA6A$261
Confirm VIN, corner and axle before ordering.
- Genuine Nissan rear ABS sensor, passenger side, M226 branch, 47900-9CA6A$261
Confirm VIN, corner and axle before ordering.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
Nissan Altima · 2007–2018
Find C1101 by make
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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?
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.
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?
Repair costs for C1101 range from $80 to $1,500, depending on the vehicle and root cause.
Which vehicles are affected by C1101?
Au7o has documented C1101 across 3 vehicle models from 2 manufacturers: Hyundai, Nissan.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.