Operation and maintenance manual

Cummins® Service Engine Model Product Identification QSB4.5 and QSB6.7
Page E-16 Section E - Engine and System Identification
The control system is identified with the letters "CM"
followed by the control system model number.
The technology identifier after the control system
designates the prevailing technology used with the
engine. (See table in this procedure for letter
designations.)
Example:
1 On-Highway automotive "X" 15 liter engine
2 Control system number 871
3 Technology supported; Electric EGR and Diesel
Particulate Filter