WABCO 400 500 320 0, Maintenance Manual

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136
Sensor Adjustment and Component Testing
Fig. 8.16
4014011a
CONTROL
PORT
DELIVERY
PORTS 2.2
DELIVERY PORTS 2.1
3. For 4S/3M installations: Repeat this test for the external modulator valve. The external relay valve is
an axle control valve. It controls the brake chambers on one or two axles. It is important that delivery
lines from Port 2 are plumbed as shown in
Figure 5.6, Figure 5.7 and Figure 5.8 . The 4S/3M system
is designed to be used with a variety of trailer con fi gurations.
4. If the air lines are not correctly routed, perform the necessary repairs.
8.6.4 Perform End of Line Test (Standard and Premium Installations)
1. Apply 12 volts DC power to the ABS.
2. Listen for the ECU/dual modulator valve assembly to click multiple times.
3. If the indicator lamp comes on for three seconds then goes out, this indicates a correct installation.
The end of line test is complete.
 If the ABS indicator lamp comes on and stays on, check the sensor installation.
 Remove the power from the ABS and raise the sensed wheels so they may be rotated.
 Apply emergency air to fi ll the air tanks and release the spring brakes so that the wheels may be
rotated. Repeat Steps 1 and 2.
 Rotate each sensed wheel — one at a time — at a rate of 1/2 revolution per second. This rate
equals a wheel speed of approximately 4 mph (7 kph).
The ABS indicator lamp should now go out and stay out indicating a correct installation. The end of line test
is complete.
4. If the ABS lamp does not go out, there is a sensor gap problem or hardware fault. Adjust the sensor
and, if necessary, perform a fault code check.
8.6.4.1 Sensor Gap Adjustment (All Installations)
Push sensor into its holder until it contacts the tooth wheel. At installation, there must be no gap between
the sensor and the tooth wheel.
Measure the AC voltage output. Value should be 0.2 volt AC when wheel is rotated at a rate of 1/2
revolution per second.
8.6.4.2 Blink Code Check (All Installations)
Use constant power activation to perform the fault code check, as follows: