Abs light on a 06 expedition

Having the vehicle checked for DTC'S - diagnostic trouble code's would be a good first step . ABS light on codes are stored . Suggest you take your vehicle to a qualified repair shop that has the knowledge an testing equipment to diagnose the problem properly .
Anti-Lock Brake System (ABS)
The 4-wheel, 4-channel anti-lock brake system (ABS) consists of the following components:

• ABS module
• Front wheel speed sensor
• Front wheel speed sensor ring (integral to the front wheel bearing)
• Hydraulic control unit (HCU)
• Rear wheel speed sensor
• Rear wheel speed sensor ring (integral to the rear halfshaft)
• Yellow ABS warning indicator
• As you can see here , it can set numerous
• DTC'S Why guess an replace parts that won't fix the problem .
• Anti-Lock Brake System (ABS) Module Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1342 ECU is Faulted ABS Module NOTE: If other DTCs are present, REPAIR them before installing a new component.
  CLEAR the DTCs. RETRIEVE the DTCs. If DTC B1342 is retrieved, INSTALL a new module. REFER to Anti-Lock Brake System (ABS) Module in this section. REPEAT the self-test. B1483 Brake Pedal Input Circuit Failure ABS Module Go To Pinpoint Test B . B1676 Battery Pack Voltage Out of Range ABS Module Go To Pinpoint Test C . B2477 Module Configuration Failure ABS Module CONFIGURE the ABS module. REFER to Section 418-01 . CLEAR the DTCs. REPEAT the self-test. If DTC B2477 is retrieved again, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . REPEAT the self-test. B2734 Pedal Travel Sensor Supply Error ABS Module Go To Pinpoint Test M . B2736 Pedal Travel Sensor Circuit Fault ABS Module Go To Pinpoint Test M . B2737 Pedal Travel Sensor Jammed Error ABS Module Go To Pinpoint Test M . B2738 Pedal Travel Sensor Velocity Error ABS Module Go To Pinpoint Test M . B2740 Pedal Travel Sensor Spike Error ABS Module Go To Pinpoint Test M . B2741 Sensor Cluster Defective ABS Module FOLLOW the diagnostic tool directions for the calibration procedure. B2900 VIN Mismatch ABS Module VERIFY that the module has the correct as-built data.
  CHECK for correct powertrain control module (PCM) and ABS module configurations using the diagnostic tool. RECONFIGURE the component as necessary. FOLLOW the diagnostic tool directions for the ABS module configuration or REFER to Section 418-01 for the PCM. CLEAR the DTC. REPEAT the self-test. C1095 ABS Hydraulic Pump Motor Circuit Failure ABS Module Go To Pinpoint Test D . C1145 Speed Wheel Sensor RF Input Circuit Failure ABS Module Go To Pinpoint Test E . C1155 Speed Wheel Sensor LF Input Circuit Failure ABS Module Go To Pinpoint Test E . C1165 Speed Wheel Sensor RR Input Circuit Failure ABS Module Go To Pinpoint Test E . C1175 Speed Wheel Sensor LR Input Circuit Failure ABS Module Go To Pinpoint Test E . C1233 Speed Wheel LF Input Signal Missing ABS Module Go To Pinpoint Test F . C1234 Speed Wheel RF Input Signal Missing ABS Module Go To Pinpoint Test F . C1235 Speed Wheel RR Input Signal Missing ABS Module Go To Pinpoint Test F . C1236 Speed Wheel LR Input Signal Missing ABS Module Go To Pinpoint Test F . C1277 Steering Wheel Angle 1 and 2 Circuit Failure ABS Module Go To Pinpoint Test G . C1278 Steering Wheel Angle 1 and 2 Signal Faulted ABS Module Go To Pinpoint Test G . C1279 Yaw Rate Sensor Circuit Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C1280 Yaw Rate Sensor Signal Fault (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C1281 Lateral Accelerometer Circuit Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C1282 Lateral Accelerometer Signal Fault (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C1285 Booster Solenoid Circuit Failure ABS Module Go To Pinpoint Test I . C1287 Booster Pedal Force Switch Circuit Failure ABS Module Go To Pinpoint Test J . C1288 Pressure Sensor Main/Primary Input Circuit Failure ABS Module Go To Pinpoint Test K . C1440 (with stability assist) Pressure Sensor Main/Primary Signal Faulted ABS Module Go To Pinpoint Test K . C1516 Roll Rate Sensor Signal Fault (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C1517 Roll Rate Sensor Circuit Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C1730 Reference Voltage Out of Range (+5V) ABS Module Go To Pinpoint Test L . C1805 Mismatched PCM and/or ABS-TC Module ABS Module CHECK for correct PCM and ABS module configuration using the diagnostic tool. RECONFIGURE the component as necessary. FOLLOW the diagnostic tool directions for the ABS module configuration or REFER to Section 303-01 for the PCM. CLEAR the DTC. REPEAT the self-test. C1963 Stability Control Inhibit Warning ABS Module This DTC is for information only. GO to the Principles of Operation. CLEAR the DTC. REPEAT the self-test. C1991 Module Calibration Failure ABS Module Follow the diagnostic tool directions for the calibration procedure. C1996 Active Yaw and/or Roll Control Disabled ABS Module This DTC can be set if the ABS module system is activated for 15 seconds of continuous operation. CHECK for any major chassis modifications, gross suspension misalignment or other items that can alter the vehicle tracking dynamics. CLEAR the DTC. REPEAT the self-test. C1998 Module Calibration Not Complete ABS Module Go To Pinpoint Test O . C2769 (ABS only) Longitudinal Acceleration Sensor Electrical Failure ABS Module INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. REPEAT the self-test. C2769 (ABS with stability assist) Longitudinal Acceleration Sensor Electrical Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C2770 (ABS only) Longitudinal Acceleration Sensor Plausibility Failure ABS Module INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. CLEAR the DTCs. REPEAT the self-test. C2770 (ABS with stability assist) Longitudinal Acceleration Sensor Plausibility Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C2777 Sensor Cluster Bus Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . C2778 Sensor Cluster Power Supply Failure (Sensor Cluster Fault) ABS Module Go To Pinpoint Test H . U1900 CAN Communication Bus Fault-Receive Error Network Fault REFER to Section 418-00 . U1901 CAN Network #2 Communication Bus Fault-Receive Error Network Fault Go To Pinpoint Test H . U2023 Fault Received from External Node Instrument Cluster REFER to Section 418-00 .