C1103: How to Diagnose & Fix — ABS/Brake System Circuit Fault (manufacturer-specific)

A failed front ABS wheel speed sensor (or its corroded/damaged wiring) is a common cause of the simultaneous ABS, VDC (vehicle dynamic control), and SLIP warning lights on the Altima. Because the sensor feeds speed data to multiple modules, one bad sensor lights several warnings and disables ABS and traction/stability control. The sensors live at the wheels and fail from road debris, corrosion, and electrical wear. Driving is possible but anti-lock braking and stability assist are inactive until repaired.

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.

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.