Wheel Sensor Inspection

Clean the encoder, and make sure no metal or other debris is stuck to the encoder surface.
Check the magnetic encoder (A) and pulser (B) for damage. If cracked or damaged, replace the encoder or pulser.
Front

Fig 1: Checking Magnetic Encoder & Pulser - Front
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Rear

Fig 2: Checking Magnetic Encoder & Pulser - Rear
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the air gap between the wheel sensor (C) and the magnetic encoder or pulser all the way around while rotating the encoder.
Standard:
1. Front: 0.5-1.2 mm (0.02-0.05 in.)
2. Rear: 0.4-1.1 mm (0.02-0.04 in.)