Technical Information
131
DDEC V Code PID SID FMI DESCRIPTION
84 101 -- 1 Crankcase Pressure Low
84 153 -- 1 Extended Crankcase Pressure Low
85 190 -- 0 Engine Overspeed
85 190 -- 14 Engine Overspeed Signal
86 73 -- 3 Pump Pressure Sensor Input Voltage High
86 108 -- 3 Barometric Pressure Sensor Input Voltage High
87 73 -- 4 Pump Pressure Sensor Input Voltage Low
87 108 -- 4 Barometric Pressure Sensor Input Voltage Low
88 20 -- 1 High Range Coolant Pressure Low
88 109 -- 1 Coolant Pressure Low
89 95 -- 0 Fuel Restriction High
89 111 -- 12 Maintenance Alert Coolant Level Fault
DIAGNOSTIC TROUBLESHOOTING CODES (DTC) — ALLISON 4
TH
GENERATION
CONTROLS
DIAGNOSTIC TROUBLESHOOTING CODES (DTC) OVERVIEW
Diagnostic codes (DTC) are numerical indications relating to a malfunction in transmission operation.
These codes are logged in a list in the TCM memory with the most severe or most recent code listed first.
A maximum of five codes (numbered d1 to d5) may be listed in memory at one time. As codes are added,
the oldest inactive code is dropped from the list. If all codes are active, the code with the lowest priority
that is not included on the severity list is dropped from the list.
Diagnostic codes (DTC) and code information may be accessed through the pushbutton shift selector or
using an Allison DOC™ diagnostic tool.
The TCM separately stores the active and inactive codes. An active code is any code that is current in the
TCM decision-making process. Inactive codes are codes that are retained in the TCM memory and will
not necessary affect the TCM decision-making process. Inactive codes are useful in determining if a
problem is:
• Isolated ;
• Intermittent ;
• Result from a previous malfunction.
The TCM may automatically delete a code from memory if it has not recurred. If the
MODE INDICATOR (LED) is not illuminated, the displayed code is not active. An
illuminated MODE INDICATOR (LED) during normal operation signifies secondary shift
mode operation.
DIAGNOSTIC CODES – ALLISON 4
TH
GENERATION CONTROLS
When the diagnostic mode is entered, the first code (position d1) is displayed as follows:
Exemple: Code P0722
Displayed as: d1…P…07…22
The code list position is the first item displayed, followed by the DTC. Each item is displayed for about
one second. The display cycles continuously until the next code list position is accessed by pressing the
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