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 AIR BAG RESTRAINT SYSTEM article. |
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
There are three data lines in the system. The 800 circuit data line is the Universal Asynchronous Receiver/Transmitter (UART) data line. It allows the Powertrain Control Module (PCM), Sensing and Diagnostic Module (SDM), HVAC Programmer, instrument cluster and Electronic Brake/Traction Control Module (EBTCM) to communicate by transmitting data.
The 1807 data line is the Class 2 data line that the PCM and Remote Function Actuator (RFA) Module communicates on. The 835 circuit is the entertainment and comfort data line, allowing communication between the HVAC programmer, Driver Information Center (DIC)/HVAC control assembly, CD changer and radio. A scan tool can be connected to the Data Link Connector (DLC), allowing the scan tool to communicate with the data lines. System operations can then be monitored for diagnostic purposes.
COMPONENT LOCATIONS
| Component | Location |
|---|---|
| Data Link Connector (DLC) | Under Driver Side Of Instrument Panel, Behind Sliding Door In Sound Insulator. (Scheme 1) |
| DIC/HVAC Control Assembly (Aurora) | Center Of Passenger Compartment, Behind Instrument Panel |
| Electronic Brake/Traction Control Module (EBTCM) | Driver Side Of Engine Compartment, Attached To Left Strut Tower. (Scheme 2) |
| HVAC Programmer | Behind Passenger Side Of Instrument Panel, Near PCM. (Scheme 3) |
| Powertrain Control Module (PCM) | Behind Passenger Side Of Instrument Panel, Near Shroud. (Scheme 4) |
| Radio | Center Of Instrument Panel |
| Remote CD Changer | Passenger Side Of Luggage Compartment |
| Remote Function Actuator (RFA) Module | Passenger Front Of Luggage Compartment, Below Rear Shelf. (Scheme 5) |
| RH Rear Power Distribution Center Fuse Block No. 1 | Under Driver Side Rear Seat. (Scheme 6) |
| Sensing And Diagnostic Module (SDM) | Below Front Passenger Seat. (Scheme 7) |
| C101 (78 Terminals) | Center Rear Of Engine Compartment. (Scheme 8) |
| C102 (30 Terminals) | Center Rear Of Engine Compartment, Near Wiper Motor Module. (Scheme 8) |
| C200 (116 Terminals) | Center Of Instrument Panel, Right Of Steering Column. (Scheme 9) |
| C215 (8 Terminals, Aurora) | Behind Driver Side Of Instrument Panel |
| G101 (L36 & L37) | Passenger Rear Corner Of Engine, Behind Power Steering Pump Assembly. (Scheme 10) |
| G101 (L47) | Passenger Rear Corner Of Engine, Near Crank Pulley. (Scheme 11) |
| G202 | Driver Front Of Cabin, Under Passenger Side Kick Panel. (Scheme 12) |
| P100 | Driver Rear Of Engine Compartment, Behind Strut Tower. (Scheme 2)and (Scheme 12) |
| P107 | Passenger Rear Of Engine Compartment, Near Strut Tower. (Scheme 13) |
| S106 (L36) | Engine Harness, Near Fuel Injector No. 4 Breakout. (Scheme 14) |
| S106 (L67) | Engine Harness, Near Fuel Injector No. 4 Breakout. (Scheme 15) |
| S211 | Body Harness, Near Turn Signal Flasher Breakout. (Scheme 16) |
| S231 | Body Harness, Near Turn Signal Flasher Breakout. (Scheme 16) |
| S255 | Instrument Panel Harness, Near Radio Breakout. (Scheme 9) |
| S290 | Body Harness, Near P500 Breakout. (Scheme 12) |
| S295 | Body Harness, Near PCM Breakout. (Scheme 13) |
| S297 | Body Harness, Near PCM Breakout. (Scheme 16) |
| S298 | Body Harness, Near P500 Breakout. (Scheme 12) |
| S427 | Body Harness, Near C303 Breakout. (Scheme 17) |
COMPONENT LOCATIONS
Scheme 1
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
Scheme 10
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Scheme 16
Scheme 17
- Check all UART 800 circuit and Class 2 1807 circuit wiring for an open or short to ground. See «WIRING DIAGRAMS»(/buick/riviera/viii-1994-1999/remont/communication-devices/#data-link-communications-system) .
- Check all 835 circuit wiring for an open or short to ground. See «WIRING DIAGRAMS»(/buick/riviera/viii-1994-1999/remont/communication-devices/#data-link-communications-system) .
- Check all components for high resistance in their ground circuits. See «WIRING DIAGRAMS»(/buick/riviera/viii-1994-1999/remont/communication-devices/#data-link-communications-system) .
- Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. These circuits may be intermittent or resistive when loaded and should be checked by monitoring the voltage drop with the system under load.
- Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary.
SERIAL DATA LINE DIAGNOSIS
Refer to flowchart. (Scheme 18)and (Scheme 19).
