Bendix Commercial Vehicle Systems TABS-6 ADVANCED SINGLE CHANNEL - Manual (Page 8)

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cAuTion: correct wheel speed sensor installation is
necessary for optimal ABS operation.
Sensors should not be installed on a lift axle.
1. For increased corrosion protection Bendix recommends
that a high‑temperature rated silicon‑ or lithium‑based
grease be applied to the interior of the mounting block,
the sensor, and to a new clamping sleeve.
2. Install the new clamping sleeve fully into the block,
with the retaining tabs toward the inside of the vehicle.
Please note that Bendix WS‑24 wheel speed sensors
must use the correct clamping sleeve to avoid problems
associated with reduced retention force, such as sensor
movement and resulting ABS trouble codes. See
Figure 4.
3. Gently push (DO NOT STRIKE) the sensor into the
mounting block hole until it bottoms out on the face of
the tone ring. Secure the cable lead wire to the knuckle/
axle housing 3-6 inches from the sensor.
4. Apply a moderate amount of dielectric non‑conductive
grease to both the sensor and harness connectors.
5. Engage the connectors, and push them together until
the lock tab snaps into place. It is permissible to use an
extra wire retainer (part number 300122, or equivalent),
if available, to hold the connectors together.
The friction fit allows the WS-24 sensor to slide back and
forth under force but to retain its position when the force is
removed. When the WS‑24 sensor is inserted all the way
into the mounting block and the wheel is installed on the
axle, the hub exciter contacts the sensor, which pushes
the sensor back. Also, normal bearing play will “bump” the
sensor away from the exciter. The combination of these
two actions will establish a running clearance, or air gap,
between the sensor and exciter.
cAuTion: wheel bearing maintenance is an important
part of keeping the wheel speed sensors in the correct
position. excessive wheel end play can result in dTcs
in cases where the sensor is pushed too far away
from the tone ring for a good signal to be produced.
maintain wheel bearings per the manufacturer's
recommendations.
8. ABS INDICATOR LAMP
Trailer‑mounted Lamp
The Bendix
® TABS‑6 ™ Adv module controls an ABS
indicator lamp to show the trailer ABS status. With power
supplied by the towing vehicle — if there is an active
Diagnostic Trouble Code (DTC), or during the bulb test at
start‑up — the module illuminates the ABS indicator lamp
by providing a 12.0 VDC signal. (The other side of the
lamp is grounded.) The ABS indicator lamp output uses
pin 5 of the 18-pin connector on the module.
Dash‑mounted Lamp (PLC Controlled)
TABS-6 Adv modules use SAE J2497 standards to support
Power Line Carrier (PLC) communication. The status of
the trailer ABS is transmitted over the ignition power wire
(the blue wire of the J560 connector) — pin 6 of the 18-pin
module connector.
If there is an active DTC, during the bulb check at start-up,
the TABS‑6 Adv module will transmit a signal over the
power line to the towing vehicle’s ECU. The towing
vehicle’s ABS controller will then illuminate the trailer ABS
indicator lamp mounted on the dash.
9. BENDIX ® WS‑24 ™ WHEEL
SPEED SENSORS
See Figure 4. Wheel speed data is provided to the TABS‑6
Adv module by the Bendix ® WS‑24 ™ wheel speed sensors.
Typically, the WS‑24 wheel speed sensor is installed in a
mounting block that is welded to the axle housing. The
WS‑24 wheel speed sensors are protected by a stainless
steel sheath. They are designed to be used with beryllium
copper clamping sleeves (sometimes referred to as a
“retainer bushing”, “friction sleeve”, or “clip”) (See Figure
4). The clamping sleeve provides a friction fit between the
mounting block bore and the WS‑24 sensor.
Vehicles have an exciter ring (or “tone ring”) as part
of the wheel assembly. (The default setting expects a
100-tooth tone ring to be used. See Section 17 for more
information.) As the wheel turns, the teeth of the exciter
ring pass the wheel speed sensor, generating an AC signal
which is delivered to the TABS-6 Adv module ECU. The
signal varies in voltage and frequency as the wheel speed
changes.
See Figure 20 for an electrical system schematic showing
wheel speed sensor connector pin locations.