Bendix Commercial Vehicle Systems TABS-6 ADVANCED SINGLE CHANNEL - Manual (Page 5)

5
5. COMPONENTS
Installations of the TABS‑6 Adv module use the following
components:
Internal:
• Electronic Control Unit (ECU): The ECU monitors
the speed sensor signals, lateral accelerometer sensor
signal and various pressure sensors (and if configured,
external spring deflection sensor) to determine when
ABS and/or TRSP intervention is required. When
needed, the ECU actuates the pressure modulator
valve to optimize the brake pressure. The ECU
monitors the system to detect and warn the driver of
any malfunctions. Diagnostic Trouble Codes (DTCs)
are stored in the ECU and can be reviewed to diagnose
the TABS‑6 Adv module system.
• Lateral Accelerometer Sensor: The lateral accel‑
erometer sensor senses the lateral movement of the
trailer and sends an electrical signal directly propor‑
tional to the trailer’s lateral acceleration to the ECU.
• Internal Load Sensor:
For air suspension systems, the load sensor port (P42)
must be plumbed to a fixed axle air ride bellows. Note:
the sensor must not be plumbed to a lift axle bellows
since they are not charged when the axle is not
being used. The function of this sensor is to monitor
the pressure and send an electrical signal directly
proportional to the trailer’s axle load to the ECU.
• Brake Demand Pressure Sensor: This sensor
monitors the trailer service brake pressure being
applied by the driver and sends an electrical signal
directly proportional to the driver’s brake demand to
the ECU.
• Brake Delivery Pressure Sensor: This sensor (P21)
monitors the trailer service brake pressure that is being
delivered to the wheel ends through, or by, the TABS‑6
Adv module system and sends an electrical signal
directly proportional to the delivered trailer service
brake pressure to the ECU.
• Modulator Relay Valve (MRV): An MRV is integrated
into the module and is controlled electrically by the
ECU to decrease, hold, or allow the full applied brake
pressure into the brake chamber to control the braking
torque at the wheels.
External:
• Wheel Speed Sensors (WSS): Located at selected
hubs, wheel speed sensors detect the rotation of indi‑
vidual wheels and send an electrical signal to the ECU
proportional to the rotational velocity. See Figure 3.
• External Load Sensor:
For spring suspension systems, an external electrical
spring deflection sensor is installed — typically as close
to the center (±5 inches) as possible of an axle with
linkage attached to the center of the axle (but muST
NoT be installed on a lift axle), See Figure 4. Vehicles
with a mechanical load sensor have the port (P42) used
for sensing the air suspension system plugged.
Note: Do Not Use
Previous WSS
Clamping Sleeves
That Have “BW”
in a Diamond
90° Speed
Sensors
Straight Speed
Sensors
Sensor
Clamping
Sleeve
Acceptable
Logo-Stamped
Sleeves
FIGURE 3 ‑ Bendix ® wS-24 ™ wheel Speed SenSorS
Load Sensor
Vertical Linkage Rod
Axle Attachment
Bracket
Axle Strap-Style
Fastener Clamp
Mounting
Bolts
Rubber
Link and
Rod
Adjustable Linkage
with Rubber Link
FIGURE 4
‑ TYpicAl
exTernAl
loAd SenSor
inSTAllATion
• Trailer ABS Indicator Lamp: Controlled by the ECU
to show the ABS status, the trailer ABS indicator lamp
illuminates when a Diagnostic Trouble Code (DTC) is
active. See Figure 5. If there are no ABS diagnostic
trouble codes present, when ignition power is applied
to the ECU, the lamp will illuminate as a bulb check
lasting typically two (2), up to six (6) seconds at most.
FIGURE 5 ‑ TrAiler-mounTed ABS indicATor lAmp