Data Link Communications System: Other Pontiac Aztek I

Conditions for Setting the DTCs

1. No valid messages are detected on the class 2 serial data circuit.
2. The voltage level detected on the class 2 serial data circuit is in one of the following conditions: High Low
3. The above conditions are met for approximately 3 seconds.

Action Taken When the DTCs Sets

The module uses default values for all parameters received on the class 2 serial data circuit.

Data Link Connector (DLC)

The data link connector (DLC) allows a scan tool to communicate with the class 2 serial data line. The DLC is a standardized 16 way connector located below the instrument panel and close to the steering column. Both the connector design and location are dictated by industry wide agreements. All DLCs are required to provide a power supply, hot at all times, to terminal 16. This circuit is used to power the scan tool. All DLCs supply a power ground at terminal 4 and a signal ground at terminal 5. The class 2 serial data circuit is provided at terminal 2 of the DLC.

Once the scan tool is connected to the class 2 serial data link through the DLC, the scan tool can be used to monitor each module for diagnostic purposes and to check for diagnostic trouble codes.

Class 2 Serial Data Link

The class 2 serial data link allows these modules to communicate data with each other

1. Body Control Module (BCM)
2. Electronic Brake Control Module (EBCM)
3. Heads Up Display (HUD)
4. HVAC Control Module (with CJ2)
5. Inflatable Restraint Sensing Diagnostic Module (SDM)
6. Instrument Panel Cluster (IPC)
7. Memory Seat Module (MSM) (with A43)
8. Powertrain Control Module (PCM)
9. Radio
10. Theft Deterrent Control Module
11. Vehicle Interface Unit (VIU) (with UG1)
12. Devices on the auxiliary power drop connector

In addition, the class 2 serial data link allows a scan tool to communicate with these modules for diagnostic and testing purposes.