Braking system

Abs (abs/tcs) hu/cm inspection

~1min read

1. Disconnect the negative battery cable.

2. Connect the SST

between the ABS (ABS/TCS) HU/CM and harness connector with the ignition switch off.


3. Attach the tester leads to the SST

and inspect voltage referring the table below.

Terminal Voltage Table (Reference)

(Engine is idling, and connector is connected unless otherwise indicated.)




*1 : With TCS

*2 : Use this terminal at factory only, not used for inspection and repair at field

Inspection Using An Oscilloscope (Reference) Wheel speed
  • ABS/TCS HU/CM terminal:

RR : A ( + ) - B ( - )

LR : C ( + ) - F ( - )

RF : D ( + ) - G ( - )

LF : E ( + ) - I ( - )


  • Oscilloscope setting:

1 V/DIV (Y), 2 ms/DIV (X), AC range

  • Vehicle condition: Driving 30 km/h
Note
  • As vehicle speed increases, period of wave shortens.
  • If there is malfunctioning in the sensor rotor, wave profile warps.
Vehicle speed output
  • ABS/TCS HU/CM terminal: V( + ) - AC ( - )

  • Oscilloscope setting:

1 V/DIV (Y), 5 ms/DIV (X), DC range

  • Vehicle condition: Driving 30 km/h
Note
  • As vehicle speed increases, period of wave shortens.

Test yourself

A quick Mazda 6 quiz: every answer comes with an explanation and a link to the manual page.