ABS HU/CM Inspection
1. Disconnect the ABS HU/CM connector..
2. Connect the negative battery cable..
3. Attach the tester lead to the ABS HU/CM wiring harness-side connector and inspect the voltage, continuity, or resistance according to the standard (reference value) in the table below.
Standard (reference)
Terminal |
Signal name |
Connected to |
Measured item |
Measured terminal (measurement condition) |
Standard |
Inspection item(s) |
A |
− |
− |
− |
− |
− |
− |
B |
Ground |
Ground point |
Continuity |
B—ground point |
Continuity detected |
|
C |
RR wheel-speed (-) |
RR ABS wheel-speed sensor |
Continuity |
C–RR ABS wheel-speed sensor connector terminal B |
Continuity detected |
|
D |
− |
− |
− |
− |
− |
− |
E |
RR wheel-speed (+) |
RR ABS wheel-speed sensor |
Continuity |
E–RR ABS wheel-speed sensor connector terminal A |
Continuity detected |
|
F |
− |
− |
− |
− |
− |
− |
G |
− |
− |
− |
− |
− |
− |
H |
CAN_H |
DLC-2 (CAN_H) |
This terminal is used for communication and cannot be used for malfunction determination during terminal voltage inspection.Perform a DTC inspection. |
|||
I |
LF wheel-speed (+) |
LF ABS wheel speed sensor |
Continuity |
I–LF ABS wheel-speed sensor connector terminal A |
Continuity detected |
|
J |
− |
− |
− |
− |
− |
− |
K |
LF wheel-speed (-) |
ABS wheel-speed sensor (LF) |
Continuity |
K–LF ABS wheel-speed sensor connector terminal B |
Continuity detected |
|
L |
CAN_L |
DLC-2 (CAN_L) |
This terminal is used for communication and cannot be used for malfunction determination during terminal voltage inspection.Perform a DTC inspection. |
|||
M |
− |
− |
− |
− |
− |
− |
N |
Power supply (System) |
Ignition switch or IG1 relay |
Voltage |
Switch the ignition to ON |
B+ |
|
Switch the ignition to off |
1 V or less |
|||||
O |
RF wheel-speed (-) |
RF ABS wheel-speed sensor |
Continuity |
O–RF ABS wheel-speed sensor terminal B |
Continuity detected |
|
P |
− |
− |
− |
− |
− |
− |
Q |
RF wheel-speed (+) |
RF ABS wheel-speed sensor |
Continuity |
Q–RF ABS wheel-speed sensor terminal A |
Continuity detected |
|
R |
− |
− |
− |
− |
− |
− |
S |
− |
− |
− |
− |
− |
− |
T |
− |
− |
− |
− |
− |
− |
U |
LR wheel-speed (+) |
LR ABS wheel-speed sensor |
Continuity |
U–LR ABS wheel-speed sensor connector terminal A |
Continuity detected |
|
V |
− |
− |
− |
− |
− |
− |
W |
LR wheel-speed (-) |
LR ABS wheel-speed sensor |
Continuity |
W–LR ABS wheel-speed sensor connector terminal B |
Continuity detected |
|
X |
− |
− |
− |
− |
− |
− |
Y |
Power supply (Solenoid operation, ABS motor operation) |
Battery |
Voltage |
Under any condition |
B+ |
|
Z |
− |
− |
− |
− |
− |
− |
Test yourself
A quick Mazda 3 quiz: every answer comes with an explanation and a link to the manual page.