ABS HU/CM INSPECTION

BME041343750W03

1. Remove the battery and battery tray.

2. Connect the SST between the ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS) and harness connector with the ignition switch off.

3. Attach the tester leads to the SST to inspect voltage by referring to the table below.

Caution
• In the event that the vehicle is to be inspected while it is being driven, make sure that the SST harness does not interfere with parts in the engine room.

Terminal Voltage Table (reference value)

(Ignition switch is at ON, and connector is connected unless indicated otherwise)

Terminal

Signal

Connected to

Test condition

Voltage (V)

Action

A
B
RR wheel-speed
RR wheel-speed sensor
Vehicle is stopped
0 (AC)
• Inspect harness (wheel-speed sensor - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect wheel-speed sensor.
• Inspect related harness.
Inspect using the wave profile.
C
F
LR wheel-speed
LR wheel-speed sensor
Vehicle is stopped
0 (AC)
Inspect using the wave profile.
D
G
RF wheel-speed
RF wheel-speed sensor
Vehicle is stopped
0 (AC)
Inspect using the wave profile.
E
I
LF wheel-speed
LF wheel-speed sensor
Vehicle is stopped
0 (AC)
Inspect using the wave profile.
H
-
-
-
-
-
J
-
-
-
-
-
L*1
Torque down inhibition
PCM
Inspect using the wave profile.
• Inspect harness (ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS) - PCM.
• Inspect PCM.
• Inspect related harness.
M*1
TCS indicator
TCS indicator light
Light illuminated
Below 1.0
• Inspect harness, fuse (battery-TCS indicator light - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
Light not illuminated
10-12
O*1
TCS OFF
TCS-OFF light
Light illuminated
Below 1.0
• Inspect harness, fuse (battery-TCS-OFF light - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
Light not illuminated
10-12
P*1
TCS-OFF switch
TCS-OFF switch
When switch is pressed
0
• Inspect harness, fuse (battery-TCS - OFF SWITCH - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS) data link connector).
• Inspect related harness.
When switch is not pressed
10-12
Q
Vehicle speed output
Instrument cluster
Vehicle is stopped.
0
• Inspect harness (ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS) - Instrument cluster).
• Instrument cluster.
• Inspect front wheel- speed sensor.
• Inspect related harness.
Inspect using the wave profile.
R*1
Torque down request
PCM
Inspect using the wave profile.
• Inspect ABS/TCS HU/CM.
• Inspect related harness.
S*1
Engine speed
PCM
Inspect using the wave profile.
• Inspect harness ABS/TCS HU/CM - PCM).
• Inspect PCM.
• Inspect related harness.
T
OBD
KLN terminal of DLC
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 harness, fuse (battery - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS)-KLN terminal).
• Inspect related harness.
U*2
-
DLC-2
-
Below 1.0
• Inspect harness, fuse (ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS)-DLC).
• Inspect related harness.
V
OBD
TBS terminal of DLC-2
When TBS terminal is opened
B+
• Inspect harness (battery-ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS)-TBS terminal).
• Inspect related harness.
When TBS terminal is shorted
Below 1.0
W
ABS warning light
ABS warning light
Illuminated
1.5 min.
• Inspect harness, fuse (battery-ABS warning light - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
Not illuminated
0.5 max.
X
Brake system warning light
Brake system warning light
Illuminated
1.5 min.
• Inspect harness, fuse (battery-Brake system warning light - ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
Not illuminated
0.5 max.
Y
Brake switch
Brake switch
Brake pedal is depressed
B+
• Inspect harness, fuse (battery-brake switch-ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
Brake pedal is released
0.5 max.
Z
Battery
Ignition switch
-
B+
• Inspect harness, fuse (battery-IG SW-ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
AA, AD
Ground
Ground
-
Below 1.0
• Inspect harness (ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS)-ground point).
• Inspect related harness.
AB
Battery (ABS motor)
Battery
-
B+
• Inspect harness, fuse (battery-ABS/TCS HU/CM (with TCS) or ABS HU/CM (without TCS).
• Inspect related harness.
AC
Battery (Solenoid valve)
Battery
-
B+

*1 :
With TCS
*2 :
Used for vehicle manufacturing, not used for ABS.

Inspection Using An Oscilloscope (Reference)

Wheel speed

• ABS (ABS/TCS) HU/CM terminal:
RF : G ( + ) - D ( - )
RR : A ( + ) - B ( - )
LF : I ( + ) - E ( - )
LR : C ( + ) - F ( - )

• Oscilloscope setting: 1 V/DIV (Y), 2 ms/DIV (X)
• Vehicle condition: Driving 30 km/h [18.6 mph]
Note
• As vehicle speed increases, period of wave shortens.
• If malfunctioning in the sensor rotor, wave profile will warp.

Torque down inhibition

• ABS/TCS HU/CM terminal: L ( + ) - AA ( - )

• Oscilloscope setting: 1 V/DIV (Y), 10 ms/DIV (X)
• Vehicle condition: Idle after warm-up (Engine speed at approximatly 650 rpm)

Torque down request

• ABS/TCS HU/CM terminal: R ( + ) - AA ( - )

• Oscilloscope setting: 1 V/DIV (Y), 5 ms/DIV (X)
• Vehicle condition: Idle after warm-up (Engine speed at approximatly 650 rpm)

Vehicle speed output

• ABS (ABS/TCS) HU/CM terminal: Q ( + ) - AA ( - )

• Oscilloscope setting: 2 V/DIV (Y), 25 ms/DIV (X)
• Vehicle condition: Driving 25 km/h [15.5 mph]
Note
• As vehicle speed increases, period of wave will shortens.

Engine speed

• ABS/TCS HU/CM terminal: S ( + ) - AA ( - )

• Oscilloscope setting: 2 V/DIV (Y), 25 ms/DIV (X)
• Vehicle condition: Idle after warm-up (Engine speed at approximatly 650 rpm)