Medium Speed Controller Area Network (MS-CAN) Operation
The MS-CAN communicates using bussed messages. The MS-CAN has an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The MS-CAN is a medium speed communication network used for the following modules
- Audio control module (ACM)
- Front controls interface module (FCIM)
- Front display interface module (FDIM)
- HVAC module
- Instrument cluster (IC)
- Satellite digital audio receiver system (SDARS) module
- Smart junction box (SJB)
High Speed Controller Area Network (HS-CAN) Operation
The HS-CAN communicates using bussed messages. The HS-CAN uses an unshielded twisted pair cable, data (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The HS-CAN is a high speed communication network used for the following modules
- 4X4 control module
- ABS module
- Instrument cluster (IC)
- Occupant classification system module (OCSM)
- PCM
- Power steering control module (PSCM)
- Restraints control module (RCM)
Principles of Operation
Configurable modules accommodate a variety of vehicle options, eliminating the need for many unique modules for one vehicle line. These modules must be configured when replaced as part of a repair procedure. Configurable modules should not be exchanged between vehicles since the settings are unique to each vehicle. Failure to configure a new module may result in incorrect operation and/or DTCs setting.
The following are the 3 different methods of configuration
- Programmable module installation (PMI)
- Module reprogramming ("flashing")
- Programmable parameters
One modules do not support all 3 methods.
Vehicle Identification (VID) Block
Some PCMs contain a memory area called a vehicle identification (VID) block. The PCM VID block commonly stores powertrain configuration items such as VIN, tire size, axle ratio, and whether or not the vehicle is equipped with speed control.