Data Communications: Other Hummer H3 I

Body Control Module (BCM) C2

Body Control Module (BCM) C2 Connector Parts Identification

Body Control Module (BCM) C2 Connector Terminal Identification

Scheme 10

Data Communication Connector Parts Identification

Data Link Connector (DLC) Terminal Identification

Circuit/System Verification

Program the body control module (BCM). Refer to Body Control Module Programming and Setup .

1. If the DTC remains current, replace the BCM. Refer to «Repair Procedures»(ref-266900-S16296419032007100900000) .

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup and programming

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.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Reference Information

Schematic Reference

Data Communication Schematics

Connector End View Reference

Data Communication Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-266894-S15536493022007100900000)
2. «Connector Repairs»(ref-266894-S39629017922007100900000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-266894-S04712775072007100900000)
4. «Wiring Repairs»(ref-266894-S03650162162007100900000)

Perform the Diagnostic Repair Verification after completing the repair.

BCM Functions

The body control module (BCM) performs multiple body control functions. The BCM can control devices directly connected to its outputs based on input information. The BCM evaluates this information and controls certain body control systems by commanding outputs on or off. The BCM control inputs can be

1. Sensors and switches that are directly connected to the BCM
2. Class 2 serial data received from other control modules connected to the class 2 serial data link.

The BCM is also capable of controlling other vehicle systems that are not directly wired to the BCM. The BCM does this by sending specific messages on the class 2 serial data link. The control module capable of performing the required function will respond to the BCM message.

The BCM controls these functions

1. Audible warnings-Refer to «Audible Warnings Description and Operation»(ref-266875-S04432868352007100900000) .
2. Automatic door locks-Refer to «Power Door Locks Description and Operation»(ref-266881-S38295587352007100900000) .
3. Automatic headlamp control-Refer to «Exterior Lighting Systems Description and Operation»(ref-266867-S13221229012007100900000) .
4. Horns-Refer to «Horns System Description and Operation»(ref-266897-S35471434282007100900000) .
5. Immobilizer-Refer to «Immobilizer Description and Operation»(ref-266915-S05129917822007100900000) .
6. Interior lighting-Refer to «Interior Lighting Systems Description and Operation»(ref-266867-S03263517042007100900000) .
7. Keyless entry-Refer to «Keyless Entry System Description and Operation»(ref-266899-S31374345822007100900000) .
8. Retained Accessory Power (RAP)-Refer to «Retained Accessory Power (RAP) Description and Operation»(ref-266895-S02821607572007100900000) .
9. Front Wipers/Washer-Refer to «Wiper/Washer System Description and Operation»(ref-266872-S19583975032007100900000) .
10. Rear Wipers/Washer-Refer to «Rear Wiper/Washer System Description and Operation»(ref-266872-S40974658622007100900000) .
11. Sunroof-Refer to «Sunroof Description and Operation»(ref-266930-S37073280732007100900000) .
12. Theft deterrent-Refer to «Content Theft Deterrent (CTD) Description and Operation»(ref-266898-S22741620222007100900000) .

Power Mode

The BCM is the power mode master (PMM). Refer to Power Mode Description and Operation for more information.

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 combination star-linear configuration, where the body control module (BCM) is connected to multiple modules. Refer to Data Communication Schematics . The following modules communicate on class 2 bus

1. The BCM
2. The electronic brake control module (EBCM)
3. The inflatable restraint sensing and diagnostic module (SDM)
4. The instrument panel cluster (IPC)
5. The powertrain control module (PCM)
6. The radio
7. The rear seat entertainment (RSE) assembly
8. The transfer case shift control module (TCSCM)
9. The vehicle communication interface module (VCIM) (OnStar®)