WABCO 400 500 320 0, Maintenance Manual, Page: 153 / 188

153
Troubleshooting
Condition
Experienced
Action to Take Troubleshooting Detail
s
Verify switch and indication
lamp cable is correctly
connected to ECU.
Ensure the switch and indication lamp cable 449 827
XXX 0 is securely connected at ECU.
Verify the Tag axle function is
activated in TOOLBOX PLUS™
Software.
From the main screen of Trailer ABS diagnostics,
select the Modify pull-down. Select GIO con fi gurations
and active settings will be displayed.
Verify the switch and indication
lamp cable 449 827 XXX 0
integrity.
Using a volt/ohm meter, check for shorted or open
circuits on the switch and indication lamp cable. Refer
to Figure 9.16.
Tag Axle
Function Will
Not Activate
Inspect the 3/2 solenoid valve
472 170 997 0.
Using an ohm meter, check the resistance across
the two pins on the 3/2 solenoid valve, it should read
(at room temperature) 9 ohms (+/- 2 ohms). Refer to
Figure 9.17.
Verify the operation of the 3/2
solenoid valve 472 170 997 0.
Apply 12v DC power and ground to pins 1 and 2 in the
3/2 valve's bayonet connector. The solenoid should
energize and dump the air on the tag axle. Removing
the power and ground will cause the tag axle air bags
to re-in
fl ate.
Check tag axle valve cable 449
408 XXX 0 integrity.
Using a volt/ohm meter, check for shorted or open
circuits on the tag axle valve cable. Refer to Figure
9.18.
Verify tag axle valve cable 449
408 XXX 0 is correctly hooked
up. Refer to Figure 9.15.
Tag Axle Will
Not Reset
Using TOOLBOX PLUS™
Software, ensure there are no
active faults. Repair and clear all active faults. Cycle the ECU power.
Ensure the tag axle system is
plumbed correctly.
Refer to Figure 9.15.
Verify ECU is reading wheel
speed.
Using TOOLBOX PLUS™ Software, perform the
Sensor Test from the Component Tests pull down.
Inspect the cab-mounted tag
axle toggle switch.
Using an ohm meter, verify the switch functionality.
Switch should be a single-pole, single-throw
toggle switch. Refer to the switch manufacturer's
documentation for electrical contact information.
Verify toggle switch installation.
The cab-mounted toggle switch is connected to the
brown and yellow wires from the switch and indication
lamp cable 449 827 XXX 0 . The green wire is unused
and capped. Refer to Figure 9.16.
Verify switch and indication
lamp cable is correctly
connected to ECU.
Ensure the switch and indication lamp cable 449 827
XXX 0 is securely connected at ECU.
Verify the switch and indication
lamp cable 449 827 XXX 0
integrity.
Using a volt/ohm meter, check for shorted or open
circuits on the switch and indication lamp cable. Refer
to Figure 9.16.