Multiplexed Electrical System Service Manual 2 Control Unit Identification Line item ten of this Control Unit Information window displays the current Vehicle Software Version. This details the current CECU software and programming date that is presently installed on the vehicle. Control unit identification can be made using a few methods: Searching using the Electronic Catalog (ECAT) Connecting using the Electronic Service Analyst (ESA) Menu Control Switch (MCS) of the information display Using ECAT or ESA are the easiest and most exact ways of determining the type of control unit in the truck.
Electronic Catalog (ECAT) Identification ECAT provides a parts list built” and Bill of Materials information for each specific truck. The catalog is searchable, and contains the part number and identification of the trucks instrument panel control unit. Upon connection, ESA recognizes if a software update has been issued for the control unit within the connected vehicle. If an update is required, ESA prompts the technician to perform the update operation.
ICU Part Number Q21-1029-X-XXX CECU Part Number Q21-1055-X-XXX CECU2 Part Number Q21-1075-X-XXX CECU3 Part Number Q21-1076-X-XXX MCS Identification Chassis Node Part Number Q21-1077-X-XXX For vehicles equipped with the information display, control unit identification is possible via the Menu Control Switch (MCS). Using the MCS knob, select the "Truck Information" menu. Use this menu to look up the "CECU SW Ver." Software version P30-1002-XXX can denote either a CECU or CECU2. The blank digits (denoted by "X") in the above part numbers represent: "-X" is the hardware revision. "-XXX" is the software boot loader version.
Electronic Service Analyst (ESA) Identification ICU Software P30-1003-XXX CECU Software P30-1002-XXX Connecting using ESA brings up a control unit information window. In this window, the sixth line item is the Control Unit Type and identifies whether the truck has an ICU or CECU. It also details the variant of the CECU. CECU2 Software P30-1002-XXX CECU3 Software P30-1008-XXX CECU3 with Chassis Node Software P30-1009-XXX CECU3 with Chassis Node Software P30-1011-XXX PM819023/KM815057 (08/14/2012) 2 - 3