Diagnostic Code Display And Clearing Procedure; Exiting Diagnostic Mode - PREVOST X3-45 Commuter 2020 Operating Manual

B-4 Allison Transmission Other Features
DIAGNOSTIC CODE DISPLAY AND
CLEARING PROCEDURE
Diagnostic codes can be read and cleared by two
methods:
Using an Allison DOC™ diagnostic tool. For
l
specific instructions on how to use an Allison
DOC™ diagnostic tool, refer to the User
Guide.
Using the pushbutton shift selector.
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To begin the diagnostic process:
1. Bring the vehicle to a stop at a safe location.
2. Apply the parking brake.
To display stored codes:
1. Simultaneously press the
(Downshift) arrow
(Prognostics enabled)
Diagnostic Display Mode. With Prognostics
disabled, press the
$(Downshift) arrow buttons twice.
2. Press the MODE button to read the next
code in the queue, if any.
To clear all active stored codes:
While in Diagnostic Mode, clear all active codes
by pressing and holding the MODE button for
approximately three seconds until the MODE
message flashes. Release the MODE button.
The MODE message
illuminated if the active DTC shown in the display
has cleared.
While in Diagnostic Mode, press and hold the
MODE button for 10 seconds to clear both active
codes and inactive codes. The MODE message
flashes a second time indicating all codes are
cleared from the queue.

EXITING DIAGNOSTIC MODE

Exit the diagnostic mode by one of the following
methods:
DOB 1300-1556
(Upshift) and
buttons five times
to access the
(Upshift) and
should not remain
PA-1639 Operator's Manual 2020 X3-45 Commuter
1. Press simultaneously the
(Downshift) arrow buttons at the same time
on the push button shift selector.
2. Press any range button «D», «N» or «R» on
the push button shift selector.
3. After approximately 10 minutes of inactivity
at the push button shift selector, the
diagnostic mode automatically exits and
returns to normal operating mode.
4. Turn off power to the TCM (shut off the
engine using the ignition key).
NOTE
Be sure to record all codes displayed before
they are cleared. This is essential for
troubleshooting.
NOTE
If clearing a code while locked in a «D» (Drive)
or «R» (Reverse) position (fail- to- range), the
transmission will still be in «D» (Drive) or «R»
(Reverse) when the clearing procedure is
completed. «N» (Neutral) must be manually
selected.
(Upshift) and