12
FIGURE 10 - EXAMPLE OF BLINK CODE MESSAGE
Troubleshooting: Blink Codes and Diagnostic Modes
BLINK CODES
Blink codes allow a technician to troubleshoot ABS problems
without using a hand-held or PC-based diagnostic tool.
Instead, information about the ABS system is communicated
by the ECU using the ABS indicator lamp to display
sequences of blinks.
Note: The ECU will not enter the diagnostic blink code
mode if the wheel speed sensors show that the vehicle is in
motion. If the ECU is in the diagnostic blink code mode
and then detects vehicle motion, it will exit the blink code
mode.
In addition, by operating the blink code switch as described
below, one of several diagnostic modes can be entered.
See Diagnostic Modes below.
Blink Code Switch Activation
When activating the blink code switch:
1. Wait at least two seconds after “ignition on.” (Except
when entering Reconfiguration Mode - see
Reconfiguration section on page 10)
2. For the ECU to recognize that the switch is activated
“on,” the technician must press for at least 0.1 seconds,
but less than 5 seconds. (If the switch is held for more
than 5 seconds, the ECU will register a malfunctioning
switch.)
3. Pauses between pressing the switch when a sequence
is required, (e.g. when changing mode) must not be
longer than 2 seconds.
4. After a pause of 3.5 seconds, the ECU will begin
responding with output information blinks. See Figure
10 for an example.
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
FIGURE 9 - TYPICAL VEHICLE DIAGNOSTIC CONNECTOR
LOCATIONS (J1708/J1587, J1939)
Located on
Dash Panel
Located Under
Dash Panel
Or
ECU DIAGNOSTICS
The EC-60
™
controller contains self-testing diagnostic
circuitry that continuously checks for the normal operation
of internal components and circuitry, as well as external
ABS components and wiring.
Active Diagnostic Trouble Codes
When an erroneous system condition is detected, the
EC-60
™
controller:
1. Illuminates the appropriate indicator lamp(s) and
disengages part or all of the ABS and ATC functions.
(See page 9.)
2. Places the appropriate trouble code information in the
ECU memory.
3. Communicates the appropriate trouble code information
over the serial communications diagnostic link as
required. Hand-held or PC-based diagnostic tools attach
to the vehicle diagnostic connector, typically located
on or under the dash (see Figure 9).
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