Visual Inspection
Remove the wheel and tire, and inspect the sensor for looseness and damage. Replace the sensor if necessary.
Clearance Inspection
Inspect the clearance between the wheel-speed sensor and the sensor rotor.
Clearance
0.3-1.1 mm {0.012-0.043 in}

Resistance Inspection
1. Disconnect the ABS wheel-speed sensor connector.
2. Inspect the resistance at the ABS wheel-speed sensor.
Resistance
1.3-1.7 kilohm
Voltage Inspection
1. On level ground, jack up the vehicle and support it evenly on safety stands.
2. Disconnect the ABS wheel-speed sensor connector.
3. Inspect each sensor by rotating each wheel one revolution per second.
Voltage
0.25-1.2 V (AC)
Voltage Pattern Inspection
1. On level ground, jack up the vehicle and support it evenly on safety stands.
2. Disconnect the ABS wheel-speed sensor connector.
3. Using an oscilloscope, inspect voltage pattern for distortion and noise by rotating each wheel.

Front abs wheel-speed sensor removal/installation
Rear abs wheel-speed sensor removal/installationMazda 6 Service Manual: Floor Mat
We recommend the use of Genuine Mazda floor mats.
WARNING
Make sure the floor mats are hooked on the retention pins to prevent them
from bunching up under the foot pedals: Using a floor mat that is not secured
is dangerous as it will interfere with the accelerator and brake pedal operation,
...
Mazda 6 Service Manual: No.8 no cool air
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while performing the inspection to discover
whether poor contact points are the cause of any intermittent malfunctions.
If there is a problem, check to make sure connectors, terminals ...