Section 06-09: Brake System, Anti-Lock | 1994 Mustang Workshop Manual |
DIAGNOSIS AND TESTING
Symptom Chart
| Condition | Possible Source | Action |
- Anti-Lock Warning Lamp Always On
|
- Fuse(s).
- Circuit.
- Front brake anti-lock sensor indicator/Rear brake anti-lock sensor.
- ABS hydraulic actuator/ anti-lock brake control module assembly.
|
|
- Anti-Lock Warning Lamp Always Off
|
- Fuse(s).
- Circuit.
- Anti-lock warning lamp bulb.
- ABS control module.
|
|
|
- Fuse(s).
- Circuit.
- Front brake anti-lock sensor indicator/Rear brake anti-lock sensor.
- ABS hydraulic actuator/ anti-lock brake control module assembly.
|
|
On-board Diagnostics
Quick Test is performed with the key ON, engine off. Prior to performing
the Quick Test, an inspection of the anti-lock warning lamp is required to
verify that a fault has indeed been detected by the ABS control module or if
the system is operating normally. When the ABS system is operating normally,
the anti-lock warning lamp will illuminate for approximately three seconds when
the key is turned ON or when the engine starts. If the anti-lock warning lamp
stays on for more than three seconds after the engine starts or illuminates
while driving, then a malfunction has occurred in the ABS system. The ABS DTCs
are stored in the ABS control module. Up to three DTCs can be stored in the ABS
control module, and they are kept in memory until they are erased. The ABS DTCs
are retrieved by the anti-lock warning lamp. The ABS DTCs may indicate
different failures. Therefore, it is recommended that the Quick Test procedure
be followed to its entirety.
Retrieving Diagnostic Trouble Codes
Using STAR Tester II
- Turn ignition switch (11572)
to OFF position.
- Locate ABS diagnostic terminal on the engine compartment power distribution
panel.
- Connect SUPER STAR II Tester connector to the ABS diagnostic connector.
ABS Diagnostic Connector

NOTE: During the reading of DTCs, the diagnostics will be discontinued and the
control module will return to normal operation if:
- The vehicle travels over 24 km/h (15 mph).
- Control module senses ungrounded diagnostic connector for more than 15
seconds.
- Ignition switch is cycled.
- Turn on SUPER STAR II tester and latch button down in TEST position. Make
sure SUPER STAR II tester is in slow mode.
- Turn ignition switch
to RUN (engine OFF). The DTCs will begin to flash. The
control module will store a maximum of three DTCs. If any DTCs have been
detected, each code will be flashed out once and only once after entering the
diagnostic mode.
- If no DTCs are stored, a DTC 12 will be output. After all DTCs have been
output, the ABS warning indicator will remain on until the ignition switch is
cycled.
