Contents Wiring diagrams Section: Communication Devices All sections

Data Communications: Overview Hummer H3 I

Communication Devices 9 illustrations ~644 words

Data Communication Schematic Icons

Data Communication Schematic Icons Icon Icon Definition CAUTION: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR DISABLING AND ENABLING . Failure to observe the correct procedure could cause deployment of the SIR components, personal injury or unnecessary SIR system repairs

Scheme 1

Scheme 1: Data Communication Schematics

Scheme 2

Scheme 2: Body Control System Schematics

Scheme 3

Scheme 3

Scheme 4

Scheme 4

Scheme 5

Scheme 5

Scheme 6

Scheme 6: Data Communication Component Views
CalloutComponent Name
1Body Control Module (BCM)
2Body Control Module (BCM) C1 (Body Harness)
3Body Control Module (BCM) C2 (I/P Harness)
4C204 I/P Harness to Body Harness

Scheme 7

Scheme 7
CalloutComponent Name
1C203 I/P Harness to HVAC Module Harness
2C205 I/P Harness to HVAC Module Harness
3Body Control Module (BCM) Connector
4C204 I/P Harness to Body Harness
5Trailer Blunt-Cut Harness Wires
6Data Link Connector (DLC)
7C208 I/P Harness to Body Harness
8C200 I/P Harness to Body Harness
9C207 I/P Harness to Body Harness
10C201 I/P Harness to Steering Column Harness

Scheme 8

Scheme 8: Body Control Module (BCM) C1
Connector Part Information OEM: 15480437 Service: 88988604 Description: 56-Way F GT 280/Micro 64 Series (BK)
Terminal Part Information Pins: A2-A6, A8-A48 Terminal/Tray: 15359541/4 Core/Insulation Crimp: M/M Release Tool/Test Probe: 15381651-2/J-35616-64A (L-BU) Pins: A7, B1-B8 Terminal/Tray: 15304711/8 Core/Insulation Crimp: Pins B3-B4, B6-B8: E/A, Pins A7, B1-B2, B5: 2/A Release Tool/Test Probe: 15315247/J-35616-4A (PU)

Body Control Module (BCM) C1 Connector Parts Identification

PinWire ColorCircuit No.Function
A1Not Used
A2YE317Fog Lamp Relay Control
A3L-BU14Left Turn Signal Lamp Supply Voltage
A4Not Used
A5PK/WH1970Headlamp Relay Control
A6BK755RAP Relay Coil Control
A7OG2040Battery Positive Voltage
A8D-GN113Windshield Wiper Switch Signal 2
A9YE1977Fog Lamp Relay Output Coil Rear
A10WH193Rear Defog Relay Control
A11L-BU244Passenger Door Lock Switch Lock Control
A12WH194Door Unlock Control
A13-A17Not Used
A18BK/WH1969Headlamp High Beam Relay Control
A19D-BU15Right Turn Signal Lamps Supply Voltage
A20YE196Windshield Wiper Motor Park Switch Signal
A21-A23Not Used
A24BN/WH301Park Lamp Relay Control
A25Not Used
A26RD/BK1594Ignition 3 Relay Control
A27-A28Not Used
A29OG1732Inadvertent Power Supply Voltage
A30OG1732Inadvertent Power Supply Voltage
A31L-BU1134Park Brake Switch Signal
A32GY/BK745Left Front Door Ajar Switch Signal (LHD)
L-GN/BK748Right Front Door Ajar Switch Signal (RHD)
A33-A35Not Used
A36L-BU74Front Position Lamp Relay Control (Export)
A37L-BU20Stop Lamp Supply Voltage
A38L-GN/BK748Right Front Door Ajar Switch Signal (LHD)
GY/BK745Left Front Door Ajar Switch Signal (RHD)
A39BK/WH746Left Rear Door Ajar Switch Signal
A40BK28Horn Relay Control
A41PU1807Class 2 Serial Data
A42PU1807Class 2 Serial Data
A43D-GN/WH762A/C Request Signal
A44L-BU/BK747Right Rear Door Ajar Switch Signal
A45Not Used
A46WH156Courtesy Lamp Low Control
A47PU1807Class 2 Serial Data
A48BN2509Left Rear Park Lamps Supply Voltage
B1YE18Left Rear Stop/Turn Lamp Supply Voltage (Domestic)
YE618Left Rear Stop/Turn Lamp Supply Voltage (Export)
B2D-GN19Right Rear Stop/Turn Lamp Supply Voltage (Domestic)
D-GN619Right Rear Stop/Turn Lamp Supply Voltage (Export)
B3BK/WH1251Ground
B4RD228Windshield Washer Pump Control
B5OG840Battery Positive Voltage
B6D-BU338Run/Crank Voltage
B7BN4Accessory Voltage
B8OG1340Battery Positive Voltage

Body Control Module (BCM) C1 Connector Terminal Identification

Circuit/System Description

The body control module (BCM) stores the last 4 digits of the sensing and diagnostic module (SDM) part number, also called restraints ID. After the BCM is reprogrammed the restraints ID is set to zero. A restraints ID relearn must be performed for the BCM to learn the restraints ID.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 2: A DTC U1001 - U1254 Lost Communications with XXX with a history status may indicate the cause of U1000 or U1255.
  2. 3: The modules not communicating are the likely cause of U1000 or U1255. The modules that are available on the class 2 serial data circuit are listed in the Circuit Description.
  3. 7: The module which was not communicating due to a poor connection to the class 2 serial data circuit may have set DTC U1001 - U1254 Lost Communications with XXX for those modules that it was monitoring.
  4. 10: The modules which can communicate indicate the module which cannot communicate. You must clear the serial data communication DTCs from these modules to avoid future misdiagnosis.
  5. 13: If all modules are communicating, the module which set U1000 or U1255 may have done so due to some other condition.
  6. 15: The module which set U1000 or U1255 is the likely cause of the malfunction.
StepActionYesNo
Schematic Reference: Data Communication Schematics Connector End View Reference: Master Electrical Component List
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Install a scan tool. Turn ON the ignition, with the engine OFF. Record the DTCs set in by each module. If using a Tech 2, use the class 2 DTC Check feature to determine which modules have DTCs set. Did you record any DTCs in the range of U1001 - U1254 with a history status?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 3
3Turn ON the ignition, with the engine OFF. Attempt to communicate with each module on the class 2 serial data circuit. If using a Tech 2, obtain this information using the class 2 Message Monitor feature. Record all of the modules communicating on the class 2 serial data circuit. Compare the list of modules which are communicating to the list given in Circuit Description. Does any module on the class 2 serial data circuit not communicate?Go to Step 4Go to Step 13
4Test the following circuits of the module that is not communicating for an open or short to ground: The battery positive voltage supply circuits The switched battery positive supply circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits Refer to the following: Control Module References for the applicable schematic Circuit Testing Wiring Repairs Did you find and correct the condition?Go to Step 9Go to Step 5
5Turn OFF the ignition. Test the ground circuits of the module that is not communicating for an open. Refer to the following: Control Module References for the applicable schematic Circuit Testing Wiring Repairs Did you find and correct the condition?Go to Step 9Go to Step 6
6IMPORTANT: Inspect all connectors in the serial data communications circuit. Refer to the following: Testing for Intermittent Conditions and Poor Connections Connector Repairs Turn OFF the ignition. Test the class 2 serial data circuits of the module that is not communicating for an open. Refer to the following: Data Communication Schematics Circuit Testing Wiring Repairs Did you find and correct the condition?Go to Step 9Go to Step 7
7Inspect the harness connector of the module that is not communicating for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The switched battery positive voltage supply The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The ground circuits The class 2 serial data circuits Refer to the following: Control Module References for the applicable schematic Testing for Intermittent Conditions and Poor Connections Connector Repairs Did you find and correct the condition?Go to Step 9Go to Step 8
8Replace the module that is not communicating. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?Go to Step 11
9Install a scan tool. Turn ON the ignition, with the engine OFF. Select the Display DTCs function for the module which was not communicating. Does the scan tool display any DTCs which do not begin with a "U"?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 10
10Use the scan tool in order to clear the DTCs. Did you complete the action?Go to Step 11
11Select the Display DTCs function for the modules which had U1000 or U1255 set as a current DTC. Does the scan tool display DTCs which do not begin with a "U"?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 12
12Use the scan tool in order to clear the DTCs. Did you complete the action?System OK
13Did you record any other DTCs for the modules which had U1000 or U1255 set as a current DTC?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 14
14Install a scan tool. Turn ON the ignition, with the engine OFF. Use the scan tool in order to clear the DTCs. Turn OFF the ignition for at least 5 seconds. Turn ON the ignition with the engine OFF. Select the Display DTCs function. Does the scan tool display U1000 set as a current DTC?Go to Step 15Go to Diagnostic Aids
15Replace the module which had U1000 or U1255 set as a current DTC. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?System OK
IMPORTANT
Inspect all connectors in the serial data communications circuit. Refer to the following: Testing for Intermittent Conditions and Poor Connections Connector Repairs

DTC U1000 and U1255

The number below refers to the step number on the diagnostic table.

  1. 7: The module which was not communicating on the class 2 serial data circuit may have set Loss of Communication DTCs for those modules that it was monitoring.
StepActionYesNo
Schematic Reference: Data Communication Schematics Connector End View Reference: Master Electrical Component List
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2IMPORTANT: Use the control module ID number list in order to determine which module is not communicating. Test the following circuits of the module that is not communicating for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following: Control Module References for the applicable schematic Circuit Testing Wiring Repairs Did you find and correct the condition?Go to Step 7Go to Step 3
3Turn OFF the ignition. Test the ground circuits of the module that is not communicating for an open. Refer to the following: Control Module References for the applicable schematic Circuit Testing Wiring Repairs Did you find and correct the condition?Go to Step 7Go to Step 4
4Test the class 2 serial data circuits of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 7Go to Step 5
5Inspect the harness connectors of the module that is not communicating for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The class 2 serial data circuits Refer to the following: Control Module References for the applicable schematic Testing for Intermittent Conditions and Poor Connections Connector Repairs Did you find and correct the condition?Go to Step 7Go to Step 6
6Replace the module which is not communicating. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?Go to Step 7
7Install a scan tool. Turn ON the ignition, with the engine OFF. Select the Display DTCs function for the module which was not communicating. Does the scan tool display any DTCs which do not begin with a "U"?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 8
8Select the Display DTCs function for the modules which had the Loss of Communications DTC set. Does the scan tool display any DTCs which do not begin with a "U"?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 9
9Use the scan tool in order to clear the DTCs. Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared. Did you complete the action?System OK
IMPORTANT
Use the control module ID number list in order to determine which module is not communicating.

DTC U1001-U1254

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

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: A partial malfunction in the class 2 serial data circuit uses a different procedure from a total malfunction of the class 2 serial data circuit. The following modules communicate on the class 2 serial data circuit: The body control module (BCM) The electronic brake control module (EBCM) The inflatable restraint sensing and diagnostic module (SDM) The instrument panel cluster (IPC) The powertrain control module (PCM) The radio The rear seat entertainment (RSE) assembly The transfer case shift control module (TCSCM) The vehicle communication interface module (VCIM)
  2. 4: The following DTCs may be retrieved with a history status, but are not the cause of the present condition. U1300 U1301 U1305
  3. 7: A state of health DTC with a history status may be present along with a U1000 or U1255 code having a current status. This indicates that the malfunction occurred when the ignition was ON.
  4. 8: Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.
  5. 18: If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.
  6. 19: The communication malfunction may have prevented diagnosis of the customer complaint.
StepActionYesNo
Schematic Reference: Data Communication Schematics Connector End View Reference: Master Electrical Component List
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Does the scan tool power up?Go to Step 3Go to Scan Tool Does Not Power Up
3Turn ON the ignition leaving the engine OFF. Attempt to communicate with each module on the class 2 serial data circuit. If using a Tech 2, obtain this information using the class 2 Message Monitor feature. Does the scan tool communicate with any module on the class 2 serial data circuit?Go to Step 4Go to Step 9
4Select the Display DTCs function for each module. If using a Tech 2, use the class 2 DTC Check feature in order to determine which modules do have DTCs set. Record all of the displayed DTCs, the DTC status and the module which set the DTC. Did you record any DTCs in the range of U1000 to U1305?Go to Step 5Go to Step 8
5Are the history DTCs U1300, U1301 or U1305 retrieved from any module?Go to Step 6Go to Step 7
6IMPORTANT: Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions. Test the class 2 serial data circuit for an intermittent short to ground or an intermittent short to voltage. Refer to the following: Testing for Intermittent Conditions and Poor Connections Circuit Testing Connector Repairs Wiring Repairs Did you find and correct the condition?Go to Step 18Go to Step 7
7Are U1000 or U1255 the only DTCs displayed in the previously specified range?Go to DTC U1000 and U1255Go to DTC U1001-U1254
8Diagnose the non-communicating module by using the DTC U1001-U1254 procedure for the module which is not communicating. Refer to DTC U1001-U1254 . Did you complete the action?Go to Diagnostic System Check - Vehicle
9Turn OFF the ignition. Disconnect the scan tool from the data link connector (DLC). Inspect for poor connections at the DLC terminals 2 and 5. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Diagnostic System Check - VehicleGo to Step 10
10Test the DLC ground circuit at terminal 5 for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Diagnostic System Check - VehicleGo to Step 11
11Repeat the following steps on the class 2 serial data circuits until the communication with body control module (BCM) is established or all modules listed below were disconnected. Disconnect the modules one by one, in the following order: Vehicle communication interface module (VCIM) Rear seat entertainment (RSE) assembly Transfer case shift control module (TCSCM) Electronic brake control module (EBCM) Inflatable restraint sensing and diagnostic module (SDM) Radio Instrument panel cluster (IPC) Powertrain control module (PCM) Turn ON the ignition, with the engine OFF. Attempt to communicate with the BCM, after each disconnected module. Does the scan tool communicate with the BCM?Go to Step 12Go to Step 15
12IMPORTANT: Perform this step only if the suspected module is IPC or Radio. Turn OFF the ignition. If the IPC is suspected module, test the class 2 serial data circuit between IPC and TCCM for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs . If the radio is suspected module, test the class 2 serial data circuit from Radio to RSE and VCIM for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 18Go to Step 13
13Inspect for poor connections at the class 2 serial data circuit of the last disconnected module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 18Go to Step 14
14Replace the last disconnected module. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?Go to Step 18
15Turn OFF the ignition. Disconnect the BCM. Test all of the BCM class 2 serial data circuits for an open, short to voltage or short to ground. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 18Go to Step 16
16Inspect for poor connections at the class 2 serial data circuit of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 18Go to Step 17
17Replace the BCM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?Go to Step 18
18Reconnect all of the disconnected modules. Install a scan tool. Turn ON the ignition, leaving the engine OFF. Wait for 10 seconds. The scan tool may require a power up reset before communication will occur due to a short on the class 2 serial data circuit. Turn OFF the scan tool prior to performing this test. Select the Display DTCs function for each module. If using a Tech 2, use the Class 2 DTC Check feature in order to determine which modules do have DTCs set. Record all of the displayed DTCs and the DTC status. Did you record any DTCs which begin with a "U" and with a current status?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 19
19Did you record any DTCs which do not begin with a "U"?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 20
20Use the scan tool in order to clear the DTCs. Did you complete the action?System OK
IMPORTANT
Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions.
IMPORTANT
Perform this step only if the suspected module is IPC or Radio.

Scan Tool Does Not Communicate with Class 2 Device

Scheme 9

Scheme 9: Body Control Module Replacement
CalloutComponent Name
IMPORTANT: The ignition switch should be in the OFF position when connecting or disconnecting the connectors to the body control module (BCM). Always disconnect the black body wiring harness connector FIRST and the gray instrument panel (I/P) wiring harness connector LAST. Always connect the black body wiring harness connector FIRST and the gray I/P wiring harness LAST. Preliminary Procedure Remove the right cowl side trim panel. Refer to Cowl Side Trim Panel Replacement . Program the body control module after replacement. Refer to Control Module References .
1Body Control Module Retainer (Qty: 2)
2Body Control Module Assembly
IMPORTANT
The ignition switch should be in the OFF position when connecting or disconnecting the connectors to the body control module (BCM). Always disconnect the black body wiring harness connector FIRST and the gray instrument panel (I/P) wiring harness connector LAST. Always connect the black body wiring harness connector FIRST and the gray I/P wiring harness LAST.

Body Control Module Replacement