Mazda 3 Service Manual: ABS HU/CM Inspection

Mazda 3 Service Manual / Brakes / Brake Control, Vehicle Dynamics / Sensors, Switches, Relays / 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	Wiring harness (B—ground point)
C	RR wheel-speed (-)	RR ABS wheel-speed sensor	Continuity	C–RR ABS wheel-speed sensor connector terminal B	Continuity detected	Wiring harness (C–RR ABS wheel-speed sensor connector terminal B)
D	−	−	−	−	−	−
E	RR wheel-speed (+)	RR ABS wheel-speed sensor	Continuity	E–RR ABS wheel-speed sensor connector terminal A	Continuity detected	Wiring harness (E–RR ABS wheel-speed sensor connector terminal A)
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	Wiring harness (I–LF ABS wheel-speed sensor connector terminal A)
J	−	−	−	−	−	−
K	LF wheel-speed (-)	ABS wheel-speed sensor (LF)	Continuity	K–LF ABS wheel-speed sensor connector terminal B	Continuity detected	Wiring harness (K–LF ABS wheel-speed sensor connector terminal B)
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+	Wiring harness (N—ignition switch or IG1 relay)
N	Power supply (System)	Ignition switch or IG1 relay	Voltage	Switch the ignition to off	1 V or less	Wiring harness (N—ignition switch or IG1 relay)
O	RF wheel-speed (-)	RF ABS wheel-speed sensor	Continuity	O–RF ABS wheel-speed sensor terminal B	Continuity detected	Wiring harness (O–RF ABS wheel-speed sensor connector terminal B)
P	−	−	−	−	−	−
Q	RF wheel-speed (+)	RF ABS wheel-speed sensor	Continuity	Q–RF ABS wheel-speed sensor terminal A	Continuity detected	Wiring harness (Q–RF ABS wheel-speed sensor connector terminal A)
R	−	−	−	−	−	−
S	−	−	−	−	−	−
T	−	−	−	−	−	−
U	LR wheel-speed (+)	LR ABS wheel-speed sensor	Continuity	U–LR ABS wheel-speed sensor connector terminal A	Continuity detected	Wiring harness (U–LR ABS wheel-speed sensor connector terminal A)
V	−	−	−	−	−	−
W	LR wheel-speed (-)	LR ABS wheel-speed sensor	Continuity	W–LR ABS wheel-speed sensor connector terminal B	Continuity detected	Wiring harness (W–LR ABS wheel-speed sensor connector terminal B)
X	−	−	−	−	−	−
Y	Power supply (Solenoid operation, ABS motor operation)	Battery	Voltage	Under any condition	B+	Wiring harness (Y–battery)
Z	−	−	−	−	−	−

Sensors, Switches, Relays

...

ABS HU/CM Removal/Installation

WARNING: If the ABS HU/CM configuration is not completed, it could result in an unexpected accident due to the ABS being inoperative. If the ABS HU/CM or ABS CM is replaced, always use t ...

Other materials:

Hazardous Driving
WARNING Be extremely careful if it is necessary to downshift on slippery surfaces: Downshifting into lower gear while driving on slippery surfaces is dangerous. The sudden change in tire speed could cause the tires to skid. This could lead to loss of vehicle control an ...

Parking Brake Cable Removal/Installation
1. Remove the following parts: a. Upper panel. b. Shift knob (MTX). c. Selector lever knob (ATX). d. Shift panel. e. Side wall. f. Console. 2. Remove the under cover.. 3. Remove the tunnel member (rear). (MZR 2.0, MZR 2.5, MZR 2.3 DISI Turbo). 4. Remove the brace bar. (SKYACTIV-G ...

Passenger Side Air Bag Module Removal/Installation [Two Step Deployment Control System]
WARNING: Handling the air bag module improperly can accidentally deploy the air bag module, which may seriously injure you. Read the air bag system service warnings and cautions before handling the air bag module.. Due to the adoption of 2-step deployment control in the passeng ...