C1103 on Nissan: How to Diagnose & Fix
ABS/Brake System Circuit Fault (manufacturer-specific)
1 Nissan model · 1 documented issue
C1103 on Nissan by model: symptoms, diagnosis and fix
The ABS/VDC control unit stores a wheel speed sensor code (C1101-C1104). Nissan's bulletin lists sensor damage, a missing sensor signal, short circuits and bent, corroded or contaminated connector pins as the things to check. 2007-2013 Nissan vehicles equipped with ABS/VDC, which includes the 2007-2012 Altima.
How to Fix
Per Nissan bulletin NTB10-102a, the technician records the active codes, clears them and road-tests above 13 mph to confirm the code returns, then checks the suspect sensor for damage, its output with a wheel sensor tester, the harness for shorts and the connectors for bent pins or corrosion before replacing anything. Nissan says not to replace a sensor based on the code alone. Normal warranty rules apply; this is not a recall or a promise of free repair. A stored code alone does not establish a failed sensor. The sensor, harness or connector repair follows the diagnostic result; do not infer that driving with a brake warning is safe.
Sources for this issue (1)
C1103 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 C1103 mean on a Nissan?
C1103 stands for "ABS/Brake System Circuit Fault (manufacturer-specific)." This is a chassis code set by the ABS/brake control module, and its precise meaning is manufacturer-specific. On many vehicles it refers to a fault in an ABS-related circuit such as the hydraulic brake switch or a wheel-speed/control circuit, while some makes (for example certain Mercedes-Benz) assign it to a specific axle circuit. In general it indicates the ABS module found an electrical problem in a brake-system input or control circuit, which can disable anti-lock braking and stability features. Because braking-related faults affect safety, it should be diagnosed against the correct service information for the specific make. On Nissan it is documented across 1 model: Altima.
What are the most common causes of C1103?
The most common causes of C1103 are: Faulty hydraulic brake/pressure switch (on applicable makes), Wheel-speed sensor or related circuit fault, Damaged, corroded, or open wiring/connectors, Poor grounds or low supply voltage to ABS module, Internal ABS/EBCM module failure, Manufacturer-specific axle/sensor circuit fault. The specific cause varies by vehicle.
How much does it cost to fix C1103 on a Nissan?
Repair costs vary widely with the root cause and Nissan model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.