TM-9-2320-283-13-P
ANTI-LOCK BRAKE SYSTEM (ABS) M915A1
TECHNICAL MANUAL; OPERATOR AND FIELD MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST (RPSTL)
AUGUST 2012
TM-9-2320-283-13-P - Page 66 of 400
TM 9-2320-283-13&P
0012
0012-2
HOW TO USE ABS DIAGNOSTICS–CONTINUED
NOTE
Use of hand-held or PC-based diagnostic tools is not covered in this
TM.
Communicate the trouble code information through the ABS diagnostic connector to a separate hand-held or
PC-based diagnostic tool. Refer to WP 0004.
In order to retrieve the trouble code information recorded in the ECU's memory for troubleshooting purposes,
the maintainer must activate blink codes and select diagnostic modes using the ABS test switch and warning
light in the tractor cab. When activated, trouble code messages from the ECU are flashed in the form of blinks.
The maintainer must count and record the number of blinks in each sequence and refer to the Troubleshooting
Tests Index to locate troubleshooting procedures.
The following procedure shall be followed to familiarize the use of blink codes and diagnostic modes for
troubleshooting the ABS.
1.
ACTIVATING BLINK CODES
a. Turn on vehicle ignition and wait at least two seconds before pressing the ABS test switch.
NOTE
The ECU will not enter the blink code mode if the vehicle is in
motion. Once in the blink code mode, if any wheel speed sensor
detects motion the ECU will exit the blink code mode.
If the ABS test switch is depressed for more than five seconds the
ECU will register a malfunctioning switch.
Each message includes a sequence of one or more groups of blinks
that must be counted and recorded by the maintainer.
Once the ECU enters the blink code mode it will automatically
remain in the active diagnostic mode and cannot be cleared via the
test switch until all blink code messages have been displayed.
b. Press and hold the ABS test switch for at least 1 second but no more than 5 seconds. This will activate
(turn on) the blink codes. Once activated, wait 3.5 seconds to receive blink code messages.
2.
READING BLINK CODE MESSAGES
a. A sequence of one or more groups of blinks is called a message. Reading a message is based on
counting the timing between blinks and adding up the number of digits in each sequence as follows:
1) A digit is equal to a blink every half second. Consecutive digits are counted up until a pause in
timing occurs. The total number of consecutive digits is recorded as a number which corresponds
to a diagnostic trouble code. For example, four blinks a half second apart equal four digits and a
blink code number of 4.
2) A 1.5 second pause ends a digit count and begins the next digit count.
3) A 2.5 second pause ends a message and begins the next digit count.
4) The ABS warning lamp will illuminate for 5 seconds indicating the end of a message.
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