Description & Operation
WARNING:
Vehicles are equipped with air bag supplemental restraint system. Before attempting ANY repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in appropriate AIR BAG RESTRAINT SYSTEMS article.
Vehicle is not equipped with a Body Control Module (BCM). Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. In addition to this, node alive messages are transmitted by each module on the class 2 serial data circuit about once every 2 seconds. When the module detects the class 2 serial data circuit shorted, the setting of all other class 2 serial communication DTCs is inhibited and a U1300, U1301, or a U1305 DTC will set.
The class 2 serial data line allows communication between modules and scan tool. Modules on the class 2 serial data line are:
- Electronic Brake Control Module (EBCM).
- Inflatable Restraint Sensing and Diagnostic Module (SDM).
- Powertrain Control Module (PCM).
- Radio (IRC).
- Vehicle Immobilizer Module (VIM).
- Vehicle Theft Deterrent Module (VTD).