Bendix Commercial Vehicle Systems TABS-6 TRAILER ABS MODULE - Manual (Page 16)

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lock washers for the frame-mount unit, or a schedule 80
(heavy gauge steel) ¾" nipple for the tank-mount unit.
Inspect the location selected for installation and clean as
necessary.
NOTE: Inspect all components, including the
replacement trailer ABS module, for any external
damage, such as cracked valve ports, electronic
housings, etc. Any components found to be damaged
should not be installed on the vehicle and must be
replaced.
1. Position and secure the unit in the original mounting
orientation (the exhaust port must point straight down):
For tank-mount modules: Install the nipple fi tting into
the modulator-valve supply port. Then rotate the entire
assembly into the tank port until secure. Over-torquing
of the tank nipple could cause damage to the valve
body.
For frame-mount modules: Torque the mounting nuts
to 180-220 in-lbs.
2. Reconnect all air hoses and plugs to the module.
Depending on the installation, additional plugs may be
necessary. Make certain that no thread sealing material
enters the valve. All air hoses and fi ttings should be
checked for leaks prior to returning the vehicle to
service.
3. Reconnect the ECU and wheel speed sensor electrical
connectors to the unit. Apply a moderate amount of
non-conductive electrical grease to each connector pin
before reconnecting.
4. The new TABS-6 module may need to be reconfi gured
for proper operation. See page 8.
5. Leakage and Operational Tests must be performed
before returning the vehicle to service.
LEAKAGE AND OPERATIONAL TESTS
1. Before performing leak tests, block the wheels.
2. Fully charge air brake system and verify proper brake
adjustment.
3. Make several trailer brake applications and check for
prompt application and release at each wheel.
4. Check the module, modulator valve(s) and all air hose
fi ttings for leakage using a soap solution:
Check the ABS solenoid body with the trailer service
brakes fully applied. If leakage is excessive, more than
a single 1" bubble within 1 minute, replace the module.
Check the relay exhaust port with the trailer service
brakes released to be sure that leakage is less than
a single 1" bubble within 3 seconds. If excessive
leakage is detected at the relay exhaust port, perform
the following test before replacing the module:
• Apply the trailer spring brakes. Recheck for leakage
around the relay exhaust port. If the exhaust port
stops leaking, this indicates a leak between the
emergency and service sides of the spring brake
chamber. However, if the relay exhaust port
continues to leak excessively, replace the TABS-6
module.
5. Apply power and monitor the power-up sequence to
verify proper system operation. See page 6.
6. Determine the current ABS confi guration by activating
blink code diagnostics or using a diagnostic tool. If
necessary, reset the ABS confi guration and allow the
module to auto-confi gure. See page 8.
7. Calibrate and set odometer parameters if necessary
using a diagnostic tool. Refer to the Odometer Function
section on page 8.
8. Where a safe location (e.g. restricted access area
or test track) is available, it is possible to road test
the ABS function by making an abrupt stop from a
vehicle speed of about 20 MPH to check for proper
function. The wheels should not enter a prolonged lock
condition and ABS function should be audible. It is the
responsibility of the technician to perform this test in a
safe location.
ABS WIRING
All connector leads of the TABS-6 module pigtail harness
are weather sealed at the connector interface and are
clearly labeled for proper installation.
Bendix provides over-molded versions of the TABS-6
wiring harness and Bendix recommends that the complete
harness be replaced if corrosion or damage occurs.
When troubleshooting ABS wiring, some general rules
should be followed where applicable.
1. Check all wiring and connectors to ensure they are
secure and free from visible damage (e.g. cuts,
abrasions, etc.).
2. Check for evidence of wire chafi ng due to poor routing,
or poor securing, of wires.
3. Check connectors for proper insertion and locking.
4. Verify that the connector pins are properly greased with
a non-conductive electrical grease compound.
5. Connector terminals must not show signs of corrosion
or exposure to the environment.
6. Never pierce wire insulation when checking for
continuity.
7. Do not deform individual pins or sockets during probing
with a volt/ohm meter.
8. It is strongly recommended to properly secure all wiring
harness and sensor leads at least every 18 inches.
9. Apply a moderate amount of non-conductive electrical
grease to each connector pin before reconnecting.