Appendix C – Allison Diagnostic Troubleshooting Codes
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DIAGNOSTIC TROUBLESHOOTING CODES (DTC) — ALLISON 5TH GENERATION
CONTROLS
DIAGNOSTIC TROUBLESHOOTING CODES (DTC) OVERVIEW
Diagnostic features are provided with the transmission control system to assist in troubleshooting of
malfunctions and/or the monitoring of specific operating parameters. When a control system malfunction
is detected, a series of Diagnostic Trouble Codes (DTCs) are used to identify and clarify the nature of the
malfunction. These DTCs are each named by a 5 character alphanumeric string that refers to a diagnostic
algorithm running pass/fail tests to help identify a malfunction in the transmission or vehicle operation.
Most DTCs have some kind of diagnostic response that the operator notices, such as an illuminated
CHECK light, selector display change, lock in range, or inhibit shifts condition.
DTCs are logged in the Transmission Control Module (TCM) memory by severity and by their active/
inactive status with the most severe and active codes listed first. A maximum of five DTCs (numbered d1-
d5) from most recent to oldest may be read from the shift selector. As DTCs are added, the oldest
inactive DTC (historic) is dropped from the list. If all DTCs are active, the DTC with the lowest priority is
dropped from the list.
An active code is any code that is current in the TCM decision-making process and has failed the DTC
test(s) associated with that specific diagnostic algorithm. Historical codes, which are by definition inactive,
are codes that are no longer failing their algorithm but are retained in the TCM in order to help the
technician analyze possible causes and provide them direction if the vehicle is brought in before they are
cleared from the queue.
DTCs can be cleared manually by the operator or they clear automatically from last (d5) to first (d1) in the
queue after a number of engine starts, without becoming active again.
USING SHIFT SELECTOR FOR ACCESSING DIAGNOSTICS INFORMATION
DTCs can be displayed on the display portion of the shift selector. A DTC is either active or historic. An
active DTC is a DTC that is current in the TCM decision-making process. Historic DTCs are retained in
the TCM memory and do not necessarily affect the TCM decision-making process.
Display Sequence
Up to five DTCs may be displayed one at a time from the selector once the diagnostic display mode has
been initiated by the operator. Each DTC is 5 characters in length. The DTC status active or inactive is
shown below the DTC.
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Shows active DTC P0730
The operator presses the MODE button to read the next OTC in the queue (if any) or requests to exit
diagnostics mode. The diagnostics mode times out and returns the selector to normal operating mode
after approximately 10 minutes of operator inactivity.
DIAGNOSTIC CODE DISPLAY AND CLEARING PROCEDURE
Diagnostic codes can be read and cleared by two methods:
o
Using an Allison DOC™ diagnostic tool. For specific instructions on how to use an Allison DOC™
diagnostic tool, refer to the User Guide.
o
Using the pushbutton shift selector.
To begin the diagnostic process:
Summary of Contents for X3-45 COACH
Page 1: ...OPERATOR S MANUAL X3 45 COACH ...
Page 2: ......
Page 3: ...COACH MANUFACTURER OPERATOR S MANUAL X3 45 COACH PA1609 December 2015 ...
Page 8: ......
Page 13: ......
Page 18: ... WARNING Unless otherwise stated do not run the engine when the engine compartment is open ...
Page 25: ...either open or shut A key is provided for unlocking the door if the option was chosen ...
Page 153: ... ...
Page 164: ......
Page 176: ......
Page 189: ...INTERIOR UNLATCH AIR VALVE 12164 ...
Page 190: ...7 4 Safety Features and Equipment UNLATCH AIR VALVE LOCATION 12209 ...
Page 192: ...an audible alarm will sound 2 The operator shall bring the vehicle to a safe stop ...
Page 213: ......
Page 220: ......
Page 239: ...9 2 Technical Information VEHICLE IDENTIFICATION NUMBER VIN 13 COACH FINAL RECORD 13 ...
Page 240: ...Technical Information 9 3 X3 45 OVERALL DIMENSIONS SIDE ELEVATION 18673_1 ...
Page 241: ...9 4 Technical Information X3 45 OVERALL DIMENSIONS TOP FRONT AND REAR VIEWS 18674_1 ...
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Page 264: ...4 Try disconnecting the CECM ...
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