ANTI-LOCK BRAKE SYSTEM TROUBLESHOOTING AND TESTING - CONTINUED
SYSTEM COMPONENTS - CONTINUED
Figure 7. ABS Modulator Valve Cable.
LAMP BULB CHECK
To make sure the ABS lamp is operating, drivers should check the lamp every time the vehicle is started. When the vehi-
cle is started, the ABS lamp should come on momentarily. If it does not come on, it could mean a burned-out bulb.
Diagnostic Methods. You can troubleshoot the system in the following ways:
Blink Code Diagnostics
Blink Code Diagnostics. Before using blink code diagnostics, you should be familiar with a few basic terms. If you
used previous versions of Rockwell WABCO blink code diagnostics, review these definitions to identify major changes.
ABS Warning Lamp. This lamp serves two purposes: it alerts drivers to an ABS fault and it is used during diag-
nostics to display the blink code.
Blink Code. A series of blinks or flashes that describe a particular ABS system fault or condition.
Blink Code Cycle. A set of two flashes with each flash separated by a one-and-one-half second pause. Blink codes
are defined in Table 2.
Blink Code Switch. A switch that activates blink code diagnostic capabilities. Switch types and locations vary,
depending on the vehicle.
Clear. The process of erasing faults from the ECU.
Diagnostics. The process of using blink codes to determine ABS system faults.
Fault. An ABS malfunction detected and stored in memory by the Rockwell WABCO ECU. System faults may be
Active or Stored.
Active Fault. A condition that currently exists in the ABS system; for example, a sensor circuit malfunction on the
left front steering axle. An active fault must be repaired before it can be cleared from memory and before you can
display additional codes.
Stored Fault. There are two types of stored faults: One type is a repaired fault that has not been cleared from the
ECU. The other type is a fault that occurred, but no longer exists, for example a loose wire that makes intermittent
contact. Because stored faults are not currently active, they do not have to be repaired before they can be cleared
System Configuration Code. A one digit code (Blink Code: 2) is displayed during the clear mode. Blink codes for
common ABS system configurations are shown in Figure 8.