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 SYSTEM article in RESTRAINTS. |
| 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 COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
There are two data lines that can be accessed with a scan tool. The UART circuit is the Powertrain Control Module (PCM) data line. It allows the PCM to communicate with a scan tool. The class 2 circuit is the data line that allows the Diagnostic Energy Reserve Module (DERM), Electronic Brake Control Module (EBCM) and PCM to communicate with a scan tool. A scan tool can be connected to the Data Link Connector (DLC), allowing the scan tool to communicate with the two data lines. System operations can then be monitored for diagnostic purposes.
COMPONENT LOCATIONS
| Component | Location |
|---|---|
| Data Link Connector (DLC) | Mounted To Instrument Panel Tie Bar, Lower Passenger Side Of Steering Column |
| Diagnostic Energy Reserve Module (DERM) | Behind Passenger Side Of Instrument Panel Compartment (Scheme 1) |
| Electronic Brake Control Module (EBCM) | Under Instrument Panel, Next To Driver Side Hinge Pillar Above Pass Through Grommet (Scheme 2) |
| Electronic Brake/Traction Control Module (EBTCM) | Under Instrument Panel, Next To Driver Side Hinge Pillar Above Pass Through Grommet (Scheme 2) |
| Keyless Entry Receiver | Behind Passenger Side Kick Panel, In Molded Pocket (Scheme 3) |
| Powertrain Control Module (PCM) | Passenger Side Of Engine Compartment, Rearward Of Shock Tower (Scheme 4) |
| C105 | Engine Compartment, Rearward Passenger Wheelhouse Attached To PCM Bracket (Scheme 5) |
| C200A (17 Terminals) | Forward Lamp To Instrument Panel Harness, Between Driver Side Kick Panel and Steering Column (Scheme 6) |
| C200D (48 Terminals) | Part Of Instrument Panel Harness, Between Driver Side Kick Panel and Steering Column (Scheme 6) |
| C210 (4 Terminals) | Instrument Panel To Engine Harness, Under Passenger Side Of Instrument Panel Behind Passenger Side Kick Panel (Scheme 7) |
| C220 (10 Terminals) | Instrument Panel To Engine Harness, Under Passenger Side Of Instrument Panel Behind Passenger Side Kick Panel (Scheme 7) |
| C230 (10 Terminals) | Instrument Panel To Engine Harness, Under Passenger Side Of Instrument Panel Behind Passenger Side Kick Panel (Scheme 7) |
| C240 (6 Terminals) | Cross Car To Instrument Panel Harness, Under Passenger Side Of Instrument Panel Behind Passenger Side Kick Panel (Scheme 7) |
| C285 (1 Terminal) | Cross Car To Instrument Panel Harness, Under Passenger Side Of Instrument Panel Behind Passenger Side Kick Panel (Scheme 7) |
| G103 (LT1) | Passenger Side Of Engine Block, Above Starter (Scheme 8) |
| G104 (L32) | Top Passenger Side Of Engine, In Intake Manifold (Scheme 9) |
| P110 | Passenger Side, In Dash Panel (Scheme 4) |
| S109 (LT1) | Engine Harness, Near PCM Breakout |
| S110 (L36) | Engine Harness, Near PCM Breakout |
| S110 (L32) | Engine Harness, Near Passenger Side Oxygen Sensor Breakout |
| S215 | Instrument Panel Harness, Before DLC Breakout |
| S216 | Instrument Panel Harness, Near Convenience Center (Firebird) Or Instrument Panel (Camaro) Breakout |
| S217 | Instrument Panel Harness, Before DLC Breakout |
| S240 | Instrument Panel Harness, Near Transmission Range Switch Breakout |
| S270 (LT1) | Forward Lamp Harness, Near ECBM Breakout |
COMPONENT LOCATIONS
Scheme 1
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
TROUBLE SHOOTING
- Ensure Cigar/Horn fuse No. 11 is not blown. Ensure grounds are clean and tight.
- 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.
DATA LINE DIAGNOSIS
Refer to flowchart. (Scheme 10)
Scheme 10
Scheme 11
WIRING DIAGRAMS
Note. VIN letter refers to 8th character of VIN.
Scheme 12
Scheme 13
Scheme 14
See also:
• AIR BAG RESTRAINT SYSTEM