22
Once the ABS indicator lamp begins displaying a sequence
of codes, it continues until all blink code messages have
been displayed and then returns to the normal operating
mode. During this time, the ECU will ignore any additional
blink code switch activation.
All trouble codes, with the exception of voltage and
J1939 trouble codes, will remain in an active state for the
remainder of the power cycle.
Voltage trouble codes will clear automatically when the
voltage returns within the required limits. All ABS functions
will be re-engaged.
J1939 trouble codes will clear automatically when
communications are re-established.
DIAGNOSTIC MODES
In order to communicate with the ECU, the controller has
several modes that the technician can select, allowing
information to be retrieved, or other ECU functions to be
accessed.
Diagnostic Modes
To enter the various diagnostic modes:
No . of
Times to
Press the
Blink Code
Switch
System Mode Entered
1
Active diagnostic trouble code retrieval
2
Inactive diagnostic trouble code retrieval
3
Clear active diagnostic trouble codes
4
System configuration check
5
Dynamometer Test Mode
7*
Reconfigure ECU
*
To enter the Reconfiguration Mode, the switch must be held
in before the application of ignition power. Once the power is
supplied, the switch is released and then pressed seven times.
CHART 2 -
DiAgnOSTiC MODES
Active Diagnostic Trouble Code Mode
For troubleshooting, typically the Active and Inactive
Diagnostic Trouble Retrieval Modes are used. The
technician presses the blink code switch once and the ABS
indicator lamp flashes a first group of two codes, and if
there are more trouble codes recorded, this is followed by
a second set of codes, etc.
(See page 26 for a directory of
these codes.)
All active trouble codes may also be retrieved
using a hand-held or PC-based diagnostic tool, such as
the Bendix
®
ACom
®
Diagnostics software.
To clear active diagnostic trouble codes (as problems
are fixed), simply clear (or “self-heal”) by removing and
re-applying ignition power. The only exception is for wheel
speed sensor trouble codes, which clear when power is
removed, re-applied, and the ECU detects valid wheel
speed from all wheel speed sensors. Alternately, codes
may be cleared by pressing the diagnostic blink code switch
3 times (to enter the Clear Active Diagnostic Trouble Code
Mode) or by using a hand-held or PC-based diagnostic
tool. Hand-held or PC-based diagnostic tools are able to
clear wheel speed sensor trouble codes without the vehicle
being driven.
Inactive Diagnostic Trouble Code Mode
The ECU stores past trouble codes and comments (such
as configuration changes) in its memory. This record is
commonly referred to as “event history.” When an active
trouble code is cleared, the ECU stores it in the event
history memory as an inactive trouble code.
Using blink codes, the technician may review all inactive
trouble codes stored on the ECU. The ABS indicator
lamp will display inactive diagnostic blink codes when the
diagnostic blink code switch is depressed and released two
times. See page 26 for the index showing trouble codes
and the troubleshooting guide page to read for help.
Inactive trouble codes, and event history, may be retrieved
and cleared by using a hand-held or PC-based diagnostic
tool, such as the Bendix
®
ACom
®
Diagnostics software.
Clearing Active Diagnostic Trouble Codes
The ECU will clear active trouble codes when the diagnostic
blink code switch is depressed and released three times.
System Configuration Check Mode
The ABS indicator lamp will display system configuration
information when the diagnostic blink code switch is
depressed and released four times. The lamp will blink
out configuration information codes using the following
patterns. (See Chart 3).
In this mode the ECU tells the technician, by means of a
series of seven blink codes, the type of ABS system that the
ECU has been set up to expect. For example, if the fourth
blink code is a two, the technician knows that a 6S/4M
sensor/modulator configuration has been set.
Dynamometer Test Mode
The Dynamometer Test Mode is used to disable ESP &
ATC when needed (e.g. when performing any vehicle
maintenance where the wheels are lifted off the ground
and moving, including dyno testing).
For Advanced ABS
controllers this mode will remain engaged even if
power to the ECU is removed and re-applied .
To exit the Dynamometer Test Mode, press and release
the blink code switch three times, or use a hand-held or
PC-based diagnostic tool.
