ABS (ABS/TCS) HU/CM INSPECTION

id041300802700

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 to the table below.

Terminal Voltage Table (Reference)

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

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

A
B
RR wheel-speed
RR wheel-speed sensor
Vehicle is stopped
0 (AC)
• Inspect related harnesses
• Inspect ABS wheel-speed sensor
• Inspect by using the wave profile.
C
F
LR wheel-speed
LR wheel-speed sensor
Vehicle is stopped
0 (AC)
• Inspect by using the wave profile.
G
D
RF wheel-speed
RF wheel-speed sensor
Vehicle is stopped
0 (AC)
• Inspect by using the wave profile.
I
E
LF wheel-speed
LF wheel-speed sensor
Vehicle is stopped
0 (AC)
• Inspect by using the wave profile.
H
-
-
-
-
-
K
-
-
-
-
-
L
-
-
-
-
-
M
-
-
-
-
-
N
-
-
-
-
-
O
CAN-H
-
-
No need to check
-
P*1
TCS OFF switch
TCS OFF switch
When switch is pressed
Below 1.0
• Inspect related harnesses
• Inspect TCS OFF switch
When switch is not pressed
B+
Q
-
-
-
-
-
R
CAN-L
-
-
No need to check
-
S
-
-
-
-
-
T
-
-
-
-
-
U*2
-
Check connector
-
No need to check
-
V
Vehicle speed output
• Cruise actuator
• Audio unit
• Auto leveling control unit
• Wiper and washer switch
Vehicle is stopped
0
• Inspect related harnesses
• Inspect ABS wheel-speed sensor
• Inspect by using the wave profile.
W
-
-
-
-
-
X
OBD
KLN terminal of DLC-2
It cannot be determined with terminal voltage whether the condition is good or bad because advanced function diagnostic output is performed with serial communication. Inspect with service codes.
• Inspect related harnesses
• Inspect ABS/TCS HU/CM
Y
Brake switch
Brake switch
Brake pedal is depressed
10-14
• Inspect related harnesses
Brake pedal is released
Below 0.5
Z
Power supply
Ignition switch
-
B+
• Inspect related harnesses
AA
Power supply (Solenoid valve)
Battery
-
B+
• Inspect related harnesses
AB
Power supply (ABS motor)
Battery
-
B+
AC
Ground
Ground
-
0
• Inspect related harnesses
AD
Ground
Ground
-
0
• Inspect related harnesses

*1 :
With TCS
*2 :
This terminal is used at the factory only, not used for inspection and repair in the field

Inspection Using An Oscilloscope (Reference)

Wheel speed

• ABS (ABS/TCS) HU/CM terminal:
RR: A (+) - B (-)
LR: C (+) - F (-)
RF: G (+) - D(-)
LF: I (+) - E (-)
• Oscilloscope setting:
1 V/DIV (Y), 2 ms/DIV (X), AC range
• Vehicle condition: Driving 30 km/h {18.6 mph}
Note
• As vehicle speed increases, the wave period shortens.
• If there is malfunctioning in the sensor rotor, the wave profile warps.

Vehicle speed output

• ABS (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 {18.6 mph}
Note
• As vehicle speed increases, the wave period shortens.