The ABS wheel-speed sensors on a Freightliner Cascadia are mounted at each wheel hub. Front sensors sit in the front wheel knuckles near the brake rotors; rear sensors sit on the rear axle housings near the wheel ends. The sensors feed the ABS control module, whose exact mounting can vary by year and configuration.
Front axle ABS sensors
To locate and identify the front-wheel sensors on a Cascadia, look at each front wheel hub area where the brake rotor sits. The sensor is a small unit pressed or bolted into the knuckle with a tip facing a tone ring on the rotor/hub assembly. The wiring harness follows the knuckle along the wheel well toward the vehicle’s main wiring harness.
Locations by wheel:
- Front left wheel: sensor mounted in the front-left wheel knuckle, near the brake rotor.
- Front right wheel: sensor mounted in the front-right wheel knuckle, near the brake rotor.
In practice, these front sensors are the visible, easily accessible wheel-end sensors and are among the first to be inspected when diagnosing ABS activity on the Cascadia’s front axle.
Rear axle ABS sensors
For the rear axle, the sensors are mounted on or near the rear axle housing at each wheel end. Like the fronts, they face a tone ring (or reluctor) integrated with the hub or axle assembly. The harness then runs along the rear frame rails toward the ABS control module.
Locations by wheel:
- Rear left wheel: sensor located on the left rear axle housing near the wheel end, aligned with the tone ring on the hub/axle assembly.
- Rear right wheel: sensor located on the right rear axle housing near the wheel end, similarly aligned with the tone ring.
Rear sensors are sometimes tucked closer to the axle tube and may be less conspicuous than the front sensors, but they share the same basic mounting principle as the front sensors.
Where the ABS control module is located
The ABS control module for Cascadia trucks is typically mounted in the cab area or near the firewall, with wiring harnesses running along the frame to each wheel-end sensor. Exact placement can vary by model year and whether the truck uses Bendix or WABCO braking electronics, so consult the vehicle’s service manual for the precise location on your specific build.
Summary
In short, the ABS sensors on a Freightliner Cascadia are wheel-end components: front sensors sit in the front wheel knuckles by the rotors, rear sensors sit on the rear axle housings by the wheels, and both sets connect to the ABS control module whose location depends on the model year and braking system configuration. If you’re troubleshooting, inspect the sensor tips, clean the reluctor/gaps, and check the wiring harnesses along the frame for damage or loose connections.