Class 2 Serial Data Circuit Right Hand Drive (RHD)

The class 2 serial data circuit on this vehicle consists of a hybrid ring and star configuration. Each module on the ring has 2 class 2 serial data circuits connected to it. If there is 1 open on the ring serial data communication will still take place. If there is more than 1 open on the ring, the modules not connected to the class 2 serial data circuit will not communicate. If there is 1 open on the star, the module not connected to the class 2 serial data circuit will not communicate. The following modules and splice packs are connected to the class 2 serial data circuit in a ring fashion:

• SP201
• SP303
• The inflatable restraint sensing and diagnostic module (SDM)
• SP300
• The dash integration module (DIM)
• The radio
• The HVAC control module
• The electronic control module (ECM)
• The electronic brake control module (EBCM)
• SP200
• The instrument panel cluster (IPC)

The star has the following 4 splice packs:

• SP201 located in the right side of the instrument panel, near the steering column, taped to the instrument panel harness.
• SP303 located in the right rear of the passenger compartment, taped to the body harness, approximately 24 cm (9.5 in) from the fuse block - right rear.
• SP300 located in the left side middle of the passenger compartment, taped to the body harness, near the carpet seam.
• SP200 located in the center of the instrument panel, near the radio.

The following devices are connected to the class 2 serial data circuit in star fashion via splice packs:

• SP201 - The DLC
• SP303
  • The right rear door module (RRDM)
  • The radio antenna module
  • The TV antenna module
  • The vehicle communication interface module (VCIM)
  • The rear integration module (RIM)
  • The memory seat module (MSM) w/A45
  • The driver door module (DDM)
  • The driver door switch assembly (DDSA)
• SP300
  • The audio amplifier
  • The left rear door module (LRDM)
  • The front passenger door module (FPDM)
• SP200 - The theft deterrent control module

Refer to Data Link Connector (DLC) Schematics and the following illustration in order to familiarize yourself with the architecture of the class 2 serial data circuit:

Fig 1: Right Hand Drive (RHD) Class 2 Loop

Courtesy of GENERAL MOTORS CORP.