Allison Transmission Motorhome Series Operator's Manual page 62

R
MODE
N
D
Figure 13. Shift Selector/Allison DOC™ Diagnostic Tool
Historical codes are codes that are retained in the TCM/ECU's memory and will
not necessarily affect the TCM/ECU decision-making process.Historical codes are
useful in determining if a problem:
• Is isolated.
• Is intermittent.
• Results from a previous malfunction.
The TCM/ECU may automatically delete a code from memory if it has not
recurred.
R
MODE
N
D
5
4
3
2
1
SHIFT
SELECTORS
PDA
ALLISON DOC™
61
PC
V07952.00.00