Bendix Commercial Vehicle Systems EC-80 ABS ATC SD - Manual (Page 14)

14
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 (DTC) retrieval
2 Inactive DTC retrieval
3 Clear active DTCs
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 3 - 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 18 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 DTCs (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 three (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.
Blink Code Timing
The ECU responds with a sequence of blink codes. The
overall blink code response from the ECU is called a
“message.” Each message includes, depending on the
mode selected by the technician, a sequence of one or
more groups of blinks. Simply record the number of blinks
for each sequence and then use the troubleshooting index
on page 18 for active or inactive trouble codes. Once you
have located the code, you will be directed to the page
that provides the applicable troubleshooting information.
NOTE:
1. Blink sequences illuminate the ABS indicator lamp for
half a second, with half‑second pauses between them.
2. Pauses between blink code digits are 1.5 seconds.
3. Pauses between blink code messages are 2.5
seconds.
4. The lamp remains on for five (5) seconds at the end of
messages.
See Figure 8 for an example showing the message: 2,1
followed by 2,2.
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.