Data Link Communication System: Other Chevrolet Silverado 1500 HD

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 under one of the following conditions: High Low
3. The above conditions are met for approximately 3 seconds.

Action Taken When the DTCs Sets

1. The module inhibits the setting of all other class 2 DTCs.
2. The module uses default values for all parameters received on the class 2 serial data circuit.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS .

Data Link Connector (DLC)

The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is required to provide the following

1. Scan tool power battery positive voltage at terminal 16.
2. Scan tool power ground at terminal 4.
3. Class 2 serial data at terminal 2.
4. Common signal ground at terminal 5.

Class 2 Serial Data Line

The class 2 serial data line on this vehicle is a star configuration. The following modules communicate on the class 2 serial data line

1. The body control module (BCM)
2. The digital radio receiver
3. The driver door module (DDM)
4. The electronic brake control module (EBCM)
5. The front passenger door module (FPDM)
6. The HVAC control module
7. The inflatable restraint sensing and diagnostic module (SDM)
8. The instrument panel cluster (IPC)
9. The memory seat module (MSM)
10. The powertrain control module (PCM)
11. The radio
12. The radio amplifier
13. The rear seat audio (RSA) controller
14. The rear seat entertainment (RSE) assembly w/U42
15. The rear wheel steering control module
16. The remote playback device-CD player w/U1S
17. The transfer case shift control module
18. The transmission control module (TCM) w/Allison Transmission
19. The theft deterrent control module
20. The vehicle communication interface module (VCIM) w/UE1

The class 2 serial data line allows a scan tool to communicate with these modules for testing purposes, checking for DTCs, and to activate/enable/disable functions. These class 2 serial data circuits are bussed together via splice packs and a data link connector (DLC)

1. SP205
2. SP206
3. SP207
4. DLC-connects the scan tool to the class 2 serial data circuits.

Refer to Data Link Communications Component Views for an illustrated view of the splice pack locations.