Lever Shift Selector.
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. Press the
DISPLAY MODE/DIAGNOSTIC
button once to access the
diagnostic display mode—press the button twice if a transmission oil level
sensor is installed.
2. Observe the digital display for codes.
— Diagnostic codes will appear one digit at a time on WTEC III
pushbutton or lever shift selectors.
— Diagnostic codes will appear two characters at a time on Allison 4
th
Generation Controls pushbutton or lever shift selectors.
3. Press the
MODE
button to see the next code—repeat for subsequent codes.
NOTE:
Be sure to record all codes displayed before they are cleared.
This is essential for troubleshooting.
To Clear Active Indicators and Inactive Codes then Resume Vehicle Operation:
1. Clear active indicators and inactive codes.
— WTEC III Controls—To clear active indicators such as the
CHECK
TRANS
light, press and hold the
MODE
button for approximately
three seconds until the MODE INDICATOR (LED)
fl
ashes. Release
the
MODE
button and active indicators will not be illuminated. To
clear inactive codes, press and hold the
MODE
button for 10 seconds.
Some codes are self-clearing and others require ignition cycles to clear.
— Allison 4
th
Generation Electric Controls—Press and hold the
MODE
button for 10 seconds to clear both active indicators and
inactive codes.
2. Begin operating as normal—have the transmission checked at the earliest
opportunity by an Allison Transmission distributor or dealer.
NOTE:
If the condition that caused the code is still present, the code
will again become active.
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