Computer/integrating Systems: Other GMC Envoy II

Body Control Module (BCM) C1

Body Control Module (BCM) C1 Connector Part Information 12110088 24-Way F Micro-Pack 100 Series (L-GY) Pin Wire Color Circuit No. Function A1 - - Not Used A2 WH 2282 Headlamp Washer Relay Control (CE4) A3 OG 1140 Battery Positive Voltage A4 BK/WH 1969 Headlamp High Beam Relay Control A5 PK/WH 1970 Headlamp Low Beam Relay Control A6 PK 5363 Inclination Sensor Low Reference (BAE) A7-A8 - - Not Used A9 TN 5458 Midgate Overhead Console Switch Up Signal (XUV) A10-A11 - - Not Used A12 WH 278 Ambient Light Sensor Signal B1 L-GN 1037 Class 2 Serial Data B2 BK 279 Ambient Light Sensor Low Reference B3 L-GN 2270 Rear Window Washer Relay Control (CD6) B4 GY/BK 2226 Instrument Panel Lamps Dimmer Switch Low Reference B5 GY 705 5-Volt Reference B6 WH 2283 12-Volt Reference B7 OG/BK 2090 Courtesy Lamps Supply Voltage B8 L-GN 1011 Remote Radio Control Signal B9 GY 391 Rear Window Wiper Switch Signal (CD6) B10 YE 1836 Security System Sensor Signal B11 GY 2521 Right Sunload Sensor Signal (CJ2) B12 L-BU/BK 2519 Left Sunload Sensor Signal (CJ2)

Body Control Module (BCM) C2

Body Control Module (BCM) C2 Connector Part Information 12110112 32-Way F Micro-Pack 100 Series (TN) Pin Wire Color Circuit No. Function E1-E2 - - Not Used E3 L-GN 80 Key In Ignition Switch Signal E4 YE 307 Headlamp Switch Flash to Pass Signal E5 GY/BK 308 Park Lamp Switch On Signal E6 PK/BK 109 Hood Ajar Switch Signal (UA2) E7 PK 1348 Headlamp On Indicator Control E8 BK 1835 Security System Sensor Low Reference E9 RD/WH 812 12-Volt Reference E10 - - Not Used E11 D-GN/WH 1317 Fog Lamp Relay and Indicator Control (T96) E12 BK 28 Horn Relay Control E13 - - Not Used E14 TN 5463 Daytime Running Lamp Override Indicator E15-E16 - - Not Used F1-F2 - - Not Used F3 D-GN 113 Windshield Wiper Switch Signal 2 F4 D-BU/WH 1495 Courtesy Lamps On Signal F5 BN/WH 1871 Headlamp Washer Switch Signal (CE4) F6 OG 192 Front Fog Lamps Switch Signal (T96) F7 L-BU 187 Rear Fog Lamps Switch Signal (T79) F8 L-GN 5462 DRL Defeat Switch Signal F9 WH 103 Headlamp Switch Headlamps On Signal F10 L-GN 11 Headlamp High Beam Supply Voltage F11 PU 328 Interior Lamp Defeat Switch Signal F12 D-BU 6252 Midgate Ajar Indicator Signal (XUV) F13 PK 5068 Intrusion Sensor Switch Disable Signal (BAE) F14 YE 710 Class 2 Serial Data F15-F16 - - Not Used

Body Control Module (BCM) C3

Body Control Module (BCM) C3 Connector Part Information 15354796 40-Way Flat Wire Pin Wire Color Circuit No. Function A1 - 2140 Battery Positive Voltage A2 - 2140 Battery Positive Voltage A3 - 748 Right Rear Door Ajar Switch Signal A4 - 1134 Park Brake Switch Signal A5 - 195 Door Lock Control A6 - 2265 Power Window Lockout Left Rear Control A7 - - Not Used A8 - 747 Left Rear Door Ajar Switch Signal A9- A10 - - Not Used A11 - 1350 Ground A12 - 1353 RAP Supply Voltage A13 - 194 Door Unlock Control A14 - 1080 Park Lamp Relay Control A15 - 5168 Power Sounder Enable Signal (BAE) A16 - 5204 Intrusion Sensor Data Signal (BAE) A17 - - Not Used A18 - 1390 Ignition 0 Voltage A19 - 39 Ignition 1 Voltage A20 - 541 Ignition 3 Voltage B1 - 230 Instrument Panel Lamps Dimming Control B2 - 230 Instrument Panel Lamps Dimming Control B3 - 690 Courtesy Lamp Supply Voltage B4 - 2240 Battery Positive Voltage B5 - 1186 Power Window Switch Right Rear Up Signal B6 - 2266 Power Window Lockout Right Rear Control B7 - 1188 Power Window Switch Right Rear Down Signal B8 - 1185 Power Window Switch Left Rear Up Signal B9 - 1187 Power Window Switch Left Rear Down Signal B10 - - Not Used B11 - 1350 Ground B12 - 24 Backup Lamp Supply Voltage B13 - 4440 Battery Positive Voltage B14 - 1382 LED Dimming Signal B15 - 543 Accessory Voltage B16 - - Not Used B17 - 4040 Battery Positive Voltage B18 - 1732 Courtesy Lamps Supply Voltage B19 - 1977 Rear Fog Lamp Relay and Indicator Control B20 - 5362 Incline Sensor Signal (BAE)

Data Link Connector (DLC)

Data Link Connector (DLC) Connector Part Information 12110250 16-Way F Metri-Pack 150 Series (BK) Pin Wire Color Circuit No. Function 1 - - Not Used 2 PU 1132 DLC Class 2 Serial Data 3 - - Not Used 4 BK 2250 Ground 5 BK/WH 751 Ground 6 D-BU 6105 High Speed GMLAN Serial Data (+) 7-13 - - Not Used 14 L-BU 6106 High Speed GMLAN Serial Data (-) 15 - - Not Used 16 OG 640 Battery Positive Voltage

Action Taken When the DTCs Sets

1. The module suspends all message transmission.
2. The module uses default values for all parameters received on the high speed GMLAN serial data circuits.
3. The module inhibits the setting of all other high speed GMLAN communication DTCs.

Intermittent

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

Retained Accessory Power (RAP) On After Timeout (Except XUV)

Retained Accessory Power (RAP) On After Timeout (Except XUV)

Retained Accessory Power (RAP) On After Timeout (XUV)

Retained Accessory Power (RAP) On After Timeout (XUV)

Retained Accessory Power (RAP) Inoperative (Except XUV)

Retained Accessory Power (RAP) Inoperative (Except XUV)

Retained Accessory Power (RAP) Inoperative (XUV)

Retained Accessory Power (RAP) Inoperative (XUV)

Control Module References

Control Module References

Data Link References

This table identifies which serial data link that a particular module uses for in-vehicle data transmission. Some modules may use more than one data link to communicate. Some modules may have multiple communication circuits passing through them without actively communicating on that data link. This table is used to assist in correcting a communication malfunction. For the description and operation of these serial data communication circuits refer to Data Link Communications Description and Operation .

Data Link References

Programming the BCM

Perform the special function for BCM "Request BCM Info. For SPS" or select Service Programming Systems, and then refer to Service Programming System (SPS) in Programming and Setup.

Programming Theft Deterrent System Components

If the 10 minute learn procedure is chosen, perform the special function for BCM "Request VTD Info. for SPS" or select Service Programming Systems, and then refer to Programming Theft Deterrent System Components in Theft Deterrent. If the Programming Theft Deterrent System Components in the Theft Deterrent procedure is not performed after a BCM replacement, one of the following conditions will occur

1. The vehicle will not be protected against theft by the Passlock System.
2. The engine will not crank or start.

This procedure also needs to be performed when replacing the passlock sensor or when replacing the PCM with one used before in a different vehicle.

Relearn Restraints ID

Perform the special function for BCM "Setup SDM Serial Number in BCM" with the scan tool.

This procedure may also need to be performed when replacing the SDM.

1. Turn the ignition OFF for 10 seconds.
2. Connect the scan tool to the data link connector.
3. Turn the ignition ON with the engine OFF.
4. Use the scan tool in order to retrieve history DTCs from all modules.
5. Clear all history DTCs.

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. Common signal ground at terminal 5
4. Class 2 signal at terminal 2
5. High speed GMLAN serial data bus (+) at terminal 6, w/5.3L
6. High speed GMLAN serial data bus (-) at terminal 14, w/5.3L

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-200362-S39978169992005102000000) in Instrument Panel, Gages and Console
2. Automatic door locks - Refer to «Power Door Locks Description and Operation»(ref-200367-S08059792822005102000000) in Doors
3. Automatic headlamp control - Refer to «Exterior Lighting Systems Description and Operation»(ref-200366-S14337181032005102000000) in Lighting Systems
4. Interior lighting - Refer to «Interior Lighting Systems Description and Operation»(ref-200366-S30565157512005102000000) in Lighting Systems
5. Keyless entry (AUO option) - Refer to «Keyless Entry System Description and Operation»(ref-200378-S09866112732005102000000) in Keyless Entry.
6. Passlock theft deterrent - Refer to «Vehicle Theft Deterrent (VTD) Description and Operation»(ref-200381-S25445097152005102000000) in Theft Deterrent.
7. Retained accessory power (RAP) - Refer to «Retained Accessory Power (RAP) Description and Operation»(ref-200358-S27665074182005102000000)

Power Mode

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

Serial Data Power Mode

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the body control module (BCM). The BCM uses 3 signals from the ignition switch. These are the Ignition 0, Ignition 1, and Accessory.

To determine the correct power mode the BCM uses

1. The state of these signals
2. The sequence of switch closures received by the BCM
3. The status of the engine run flag

The chart indicates the power modes detected and transmitted by the BCM

Correct Ignition Switch Inputs

Serial Data Messages

The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid BCM message until they receive the engine status from the powertrain control module (PCM). If the BCM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is true, indicating that the engine is running, the modules fail-safe to Run. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is false, indicating that the engine is not running, the modules fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Discrete Ignition Signals

Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid BCM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, B+, the modules will fail-safe to the RUN power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to OFF-AWAKE. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Serial Data Control of Retained Accessory Power (RAP)

The class 2 modules receive the power mode message from the body control module (BCM) over the serial data circuits, indicating when the retained accessory power (RAP) power mode is current. The BCM monitors the ignition switch position, battery condition and passenger compartment doors status to determine whether RAP should be initiated. The modules then support the operation of the systems under their control as required by their RAP power mode operation.

RAP will end when one of the following conditions is met

1. The BCM receives an input indicating the opening of any compartment door.
2. The BCM internal timer for the RAP expires after approximately 10 minutes.
3. The BCM detects a decrease in battery capacity below a prescribed limit.

The BCM then sends a serial data power mode message Off-Awake ending the RAP function.

The class 2 RAP functions are

1. The power windows
2. The entertainment devices
3. The DIC

BCM/Relay Control of Retained Accessory Power (RAP)

The BCM keeps the RAP relay energized during all power modes, except Off-Awake.

The devices powered through the RAP relay or controlled directly by BCM are

1. The rear vent windows
2. The sunroof

The devices controlled by the BCM through the RAP supply voltage circuit are

1. The power roof module (PRM)
2. The mid-gate glass