Its common for abs sensors to become dirty especially on recreational vehicles so check and clean.
Also its important to check the wheel bearings are not out of adjustment.
Code readers/scan tools are only a diagnostic aid to work alongside other diagnostic aids.
Get hold of an accurate multimeter and some thin probes.
The resistance for the front sensors measured at the abs multiplug on pins A2&B2 (left front) is between 2100-2600 Ohms . the right hand side uses pins A3&B3 also between 2100-2600 Ohms.
The rear wheels are pins A4&B4 and a reading between 1100-1700 Ohms.
The output from the sensor is checked at the wheel, lift vehicle, disconnect the sensor and rotate the wheel by hand ( a brisk 60rpm) the output from the sensor should be measured in Volts AC with a reading around 0.1Vac minimum, (best to check with a scope if you have one)
The tightening toque for the sensor is 11Nm.