Contents Wiring diagrams Section: Communication Devices All sections

Computer/integrating Systems: Overview Pontiac GTO IV

Communication Devices 13 illustrations ~1345 words

Scheme 1

Scheme 1: Body Control System Schematics

Scheme 2

Scheme 2

Scheme 3

Scheme 3

Scheme 4

Scheme 4

Scheme 5

Scheme 5: Data Link Connector (DLC) Schematics

Scheme 6

Scheme 6

Scheme 7

Scheme 7: Retained Accessory Power (RAP) Schematics

Scheme 8

Scheme 8

Scheme 9

Scheme 9: Computer/Integrating Systems Component Views
CalloutComponent Name
1Body Control Module (BCM)
2BCM Connector-1
3BCM Connector-2
4BCM Connector-3
5BCM Connector-4

Scheme 10

Scheme 10
CalloutComponent Name
1Powertrain Integration Module

Body Control Module (BCM) C1 Connector Part Information 7283-8622-40 22-Way Female (GY) Pin Wire Color Circuit No. Function 1 YE 196 Windshield Wiper Motor Park Switch Signal 2 BN/WH 243 Accessory Voltage 3 BU 1315 Right Front Turn Signal Lamp Supply Voltage 4 L-BU 1314 Left Front Turn Signal Lamp Supply Voltage 5 GY 230 Instrument Panel Lamps Dimming Control 6 WH/RD 103 Headlamp Switch Headlamp On Signal 7 - - Not Used 8 YE 1351 Ground 9 BN/BK 755 RAP Relay Coil Control 10 OG/BK 740 Battery Positive Voltage 11 BK/GN 151 Ground 12 GN 96 Windshield Wiper Switch Pulse Delay Signal 13 OG/RD 140 Battery Positive Voltage 14 BN/GN 219 Keyless Entry Antenna Low Reference 15 OG/BK 335 Low Speed Cooling Fan Relay Control 16 WH 1393 Courtesy Lamps Supply Voltage 17 BK/YE 28 Horn Relay Control 18 BK/RD 681 Secondary Rear Defog Switch Signal 19 RD/BK 762 A/C Request Signal 20 BK/YE 251 Ground 21 L-BU 264 Security Indicator Lamp Supply Voltage 22 OG/PU 440 Battery Positive Voltage

Body Control Module (BCM) C2 Connector Part Information 7283-8621-40 12-Way Female (GY) Pin Wire Color Circuit No. Function 1 YE 218 Keyless Entry Antenna Signal 2 YE/BK 1784 Twilight Sentinel Enable Signal 3 WH 44 Instrument Panel Lamps Dimmer Switch Signal 4 GY/BK 477 Windshield Wiper Switch Signal 1 5 RD/BK 800 UART Serial Data (Primary) 6 WH/GN 774 UART Serial Data (Tertiary) 7 PU/RD 1073 Ignition Key Resistor Signal 8 - - Not Used 9 GN/WH 1061 UART Serial Data (Secondary) 10 BK 306 Headlamp Switch Headlamps Off Signal 11 RD/WH 109 Hood Ajar Switch Signal 12 OG 292 Rear Defog Switch Signal

Scheme 11

Scheme 11: Computer/Integrating Systems Connector End Views

Body Control Module (BCM) C3 Connector Part Information 7283-1766-10 16-Way Female (WH) Pin Wire Color Circuit No. Function 1 BK/GN 150 Ground 2 OG 300 Ignition 3 Voltage 3 BU/WH 112 Windshield Wiper Switch Signal 1 4 BN/WH 4 Accessory Voltage 5 RD/WH 66 A/C Request Signal 6-7 - - Not Used 8 BK/RD 1576 Rear Compartment Lid Release Switch Signal 9 GN 63 Blower Motor Medium 1 Control 10 YE/RD 314 Radio On Signal 11 YE/BU 263 Tamper Switch Signal 12 - - Not Used 13 L-BU 228 Windshield Washer Pump Control 14 - - Not Used 15 GN 1149 Content Theft Horn Control 16 BN 111 Hazard Switch Signal

Scheme 12

Scheme 12

Body Control Module (BCM) C4 Connector Part Information 7283-1767-10 26-Way Female (WH) Pin Wire Color Circuit No. Function 1 BK/RD 294 Door Lock Actuator Unlock Control 2 RD/GN 56 Rear Compartment Lid Release Control 3 YE/BU 328 Interior Lamp Switch Signal 4 WH 745 Left Front Door Ajar Switch Signal 5 BN/OG 194 Door Unlock Control 6 YE/GN 744 Rear Compartment Lid Ajar Switch Signal 7 - - Not Used 8 BU/BK 694 Driver Door Lock Actuator Unlock Control 9 PU 5171 Dead Lock Actuator Lock Control 10 BK/YE 295 Door Lock Actuator Lock Control 11 OG/YE 638 Power Window Motor Driver Down Control 12 GN/BK 167 Power Window Right Front Down Control 13 GN/OG 667 Power Window Motor Right Front Down Control 14 BU/WH 666 Power Window Motor Right Front Up Control 15 GN 164 Power Window Motor Left Front Up Control 16 L-GN/YE 781 Driver Door Lock Switch Unlock Signal 17 BN/WH 780 Driver Door Lock Switch Lock Signal 18 - - Not Used 19 GY/WH 746 Right Front Door Ajar Switch Signal 20 BN/RD 195 Door Lock Control 21 PU 157 Courtesy Lamp Control 22 WH/GN 660 Left Courtesy Lamp Control 23-24 - - Not Used 25 YE 165 Power Window Motor Left Front Down Control 26 BU 1136 Power Window Master Switch Left Front Down Signal

Scheme 13

Scheme 13

Begin diagnosis with the Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check will provide the following information

  1. The identification of the control modules which command the system
  2. The ability of the control modules to communicate through the serial data circuit
  3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Test Description

  1. 2: This step determines if the PIM is configured for manual transmission.
  2. 5: This step tests the PIM ground circuits and supply voltage.
  3. 6: This step tests the PIM harness connector for serviceability.
StepActionYesNo
Schematic Reference: Cruise Control Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Switch the ignition to OFF for 30 seconds. Operate the vehicle within the conditions for setting DTC B1019. Using the scan tool, select the DTC display function. Does DTC B1019 fail this ignition cycle?Go to Step 3Go to Diagnostic Aids
3Using the scan tool, verify that the powertrain interface module (PIM) is configured for manual transmission. Is the PIM configured for a manual transmission?Go to Step 4Go to Step 5
4Using the scan tool, configure the PIM for an automatic transmission. Is the PIM configuration complete?Go to Step 8Go to Step 5
5Test all ground circuits of the PIM for a high resistance or an open circuit fault condition. Test the PIM ignition supply voltage circuit for a high resistance, open circuit or short to ground fault condition. Has any fault been found and rectified?Go to Step 8Go to Step 6
6Inspect for poor connections at the PIM wiring connector. Has any fault been found and rectified?Go to Step 8Go to Step 7
7Replace the PIM. Refer to Powertrain Interface Module (PIM) Replacement . Has the repair been completed?Go to Step 8
8Using the scan tool, clear the DTCs. Switch the ignition to OFF for 30 seconds. Start the engine. Operate the vehicle within the conditions for running the DTC. Does DTC B1019 fail this ignition cycle?Go to Step 2System OK

DTC B1019: ROM Configuration Mismatch

  1. 3: This step verifies if the PIM and ECM have been linked together.
  2. 4: This step ensures there are no problems within the BCM system that may cause DTC B3924 to set.
  3. 6: This step tests the PIM ground circuits and supply voltage.
  4. 7: This step tests the PIM harness connector for serviceability.
StepActionYesNo
Schematic Reference: Cruise Control Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Switch the ignition to OFF for 30 seconds. Operate the vehicle within the conditions for setting DTC B3924. Using the scan tool, select the DTC display function. Does DTC B3924 fail this ignition cycle?Go to Step 3Go to Diagnostic Aids
3Using the scan tool, perform the body control module (BCM) Link to powertrain interface module (PIM) procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration . Was the linking procedure performed correctly?Go to Step 8Go to Step 4
4Test the BCM system by performing the Diagnostic System Check-Vehicle. Refer to Diagnostic System Check - Vehicle . Has any fault been found and rectified?Go to Step 8Go to Step 5
5Test all ground circuits of the PIM for a high resistance or an open circuit fault condition. Test the PIM ignition supply voltage circuit for a high resistance, open circuit or short to ground fault condition. Has any fault been found and rectified?Go to Step 8Go to Step 6
6Inspect for poor connections at the PIM wiring connector. Has any fault been found and rectified?Go to Step 8Go to Step 7
7Replace the PIM. Refer to Powertrain Interface Module (PIM) Replacement . Has the repair been completed?Go to Step 8
8Using the scan tool, clear the DTCs. Switch the ignition to OFF for 30 seconds. Start the engine. Operate the vehicle within the conditions for running the DTC. Does DTC B3924 fail this ignition cycle?Go to Step 2

DTC B3924: Wrong Environment Identifier Received From BCM

  1. 4: This step inspects the PIM ground circuits and supply voltage.
  2. 5: This step inspects the PIM harness connector.
StepActionYesNo
Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Switch the ignition to OFF for 30 seconds. Turn the ignition to ON. Using the scan tool, select the DTC display function. Do not attempt to perform any the scan tool function that requires the PIM security code to be entered. Does DTC P1611 set this ignition cycle?Go to Step 5Go to Step 3
3Using the scan tool, attempt a programming function that requires the powertrain interface module (PIM) security code to be entered. Refer to Body Control Module (BCM) Programming/RPO Configuration . Was the programming function successfully performed?System OKGo to Step 4
4Test all ground circuits of the PIM for a high resistance or an open circuit condition. Test the PIM ignition supply voltage circuit for a high resistance, open circuit or short to ground condition. Has a fault been found and repaired?Go to Step 7Go to Step 5
5Inspect for poor connections at the PIM wiring connector. Has any fault been found and corrected?Go to Step 7Go to Step 6
6Replace the PIM. Refer to Powertrain Interface Module (PIM) Replacement . Has the repair been completed?Go to Step 7
7Using the scan tool, clear the DTCs. Switch OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the conditions for running the DTC. Does DTC P1611 set this ignition cycle?Go to Step 2System OK

DTC P1611: Wrong Security Code Entered

  1. 3: This step checks if the scan tool can communicate with the BCM.
  2. 6: This step tests the PIM harness connector for serviceability.
StepActionYesNo
Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Using the scan tool, clear the DTCs. Switch OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the conditions for running the DTC. Does DTC U1304 set this ignition cycle?Go to Step 3System OK
3Using the scan tool, view the body control module (BCM) identification information. Does the scan tool display the BCM identification information?Go to Step 4Go to
4Using the scan tool, view the BCM Normal Mode Data. Does the scan tool display normal mode data?Go to Step 5Go to
5Inspect for poor connections at the powertrain interface module (PIM) wiring connector. Has any fault been found and rectified?Go to Step 7Go to Step 6
6Replace the PIM. Refer to Powertrain Interface Module (PIM) Replacement . Has the repair been completed?Go to Step 7
7Using the scan tool, clear the DTCs. Switch OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the conditions for running the DTC. Does DTC U1304 set this ignition cycle?Go to Step 2System OK

DTC U1304: Loss Communication with UART System

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

  1. 3: If BCM detects an open in its class 2 circuit, the RCDLR takes control of the Run/Crank relay.
  2. 4: A power moding code needs to be diagnosed first.
  3. 6: The scan tool communicate with VCIM via class 2, so for high speed GMLAN data link diagnostic the VCIM will not be considered.
  4. 18: The module which was not communicating due to an open in the high speed GMLAN serial data circuits may have set Loss of Communication DTCs for those modules that it was monitoring.
  5. 20: The modules which can communicate indicate the module which cannot communicate. You must clear the DTC from these modules to avoid future misdiagnosis.
StepActionYesNo
Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Install a scan tool. Turn ON the ignition, with the engine OFF. Attempt to communicate with the Engine Control Module (ECM). Were you able to communicate with ECM?Go to Step 11Go to Step 3
3Turn ON the ignition, with the engine OFF. With the scan tool check the Run/Crank Relay Command parameter from BCM Data Display under Computer/Integrating System menu. Does the scan tool display OFF?Go to Step 4Go to Step 6
4Retrieve DTCs from Body Control Module. Is the DTC B1440 set?Go toGo to Step 5
5Turn the ignition OFF. Disconnect the BCM. Test the class 2 serial data circuit of the BCM for an open. Refer to and in Wiring Systems. Did you find and correct the condition?Go to Step 19Go to Step 16
6Attempt to communicate with electronic suspension control (ESC) module. Were you able to communicate with ESC module?Go to Step 11Go to Step 7
7Turn OFF the ignition. Disconnect the vehicle communications interface module (VCIM). Bypass the VCIM installing jumpers between GMLAN serial data circuits at the VCIM connector: Connect a jumper between high speed GMLAN bus (+) circuit to BCM and high speed GMLAN bus (+) circuit to the ESC module. Connect a jumper between high speed GMLAN bus (-) circuit to BCM and high speed GMLAN bus (-) circuit to the ESC module. Attempt to communicate with ESC module. Were you able to communicate with ESC module?Go to Step 8Go to Step 10
8Test the high speed GMLAN serial data circuits of the VCIM for poor connections. Did you find and correct the condition?Go to Step 20Go to Step 9
9Replace the VCIM. Refer to Did you complete the replacement?Go to Step 20
10Turn OFF the ignition. Test all the high speed GMLAN serial data circuits between BCM and ESC module for an open. Refer to the following: Did you find and correct the condition?Go to Step 20Go to Step 11
11IMPORTANT: Use the GMLAN ID table to determine the closest module to data link connector (DLC) which 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 circuits The battery voltage output circuits The switched battery positive voltage circuits Refer to the following:Did you find and correct the condition?Go to Step 20Go to Step 12
12Turn OFF the ignition. Test the ground circuits of the module that is not communicating, for an open. Refer to the following: Did you find and correct the condition?Go to Step 20Go to Step 13
13Test the high speed GMLAN serial data circuits of the module that is not communicating, for an open. Refer to the following: Did you find and correct the condition?Go to Step 18Go to Step 14
14Test the following circuits of the module that is not communicating, for poor connections: The battery positive voltage circuits The battery voltage output circuits The switched battery positive voltage circuits The ground circuits The high speed GMLAN serial data circuits Did you find and correct the condition?Go to Step 20Go to Step 15
15Replace the module that is not communicating. Did you complete the replacement?Go to Step 20
16Inspect for poor connections at the harness connector of the BCM. Did you find and correct the condition?Go to Step 20Go to Step 17
17Replace the BCM. Did you complete the replacement?Go to Step 20
18Install a scan tool. Turn ON the ignition, with the engine OFF. Retrieve DTCs from the module that was not communicating. Does the scan tool display any DTCs which do not begin with a "U"?Go to the Diagnostic System Check - Vehicle in Vehicle DTC InformationGo to Step 19
19Use the scan tool in order to clear the DTCs. Did you complete the action?Go to Step 20
20Retrieve DTCs from 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 the Diagnostic System Check - Vehicle in Vehicle DTC InformationGo to Step 21
21Use 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 GMLAN ID table to determine the closest module to data link connector (DLC) which is not communicating.

DTC U2105 To U2199: Lost Communication With Engine Control Module (ECM)

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the applicable diagnostic system check before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data line.
  2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Data Link Communications Description and Operation»(ref-201041-S02353993382005102400000) .

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

  1. 4: If the battery positive voltage and ground circuits of the DLC are functioning properly. The malfunction must be due to the scan tool.
StepActionYesNo
Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views
1Test the battery positive voltage circuit of the DLC for an open or a short to ground. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Diagnostic Starting Point - VehicleGo to Step 2
2Test the ground circuit from pin 4 of the DLC for an open or high resistance. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Diagnostic Starting Point - VehicleGo to Step 3
3Inspect for poor connections and terminal tension at the DLC. Refer to Testing for Intermittent Conditions and Poor Connections or Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Diagnostic Starting Point - VehicleGo to Step 4
4The scan tool may be malfunctioning. Refer to the scan tool user guide. Did you obtain a properly operating scan tool?Go to Step 1

Scan Tool Does Not Power Up

Abbreviations

Abbreviations are used in this section to represent the following components

  1. BCM - Body control module
  2. ECM - Engine control module
  3. PIM - Powertrain interface module
  4. RF - Radio frequency
  5. MFD - Multifunction display, part of the instrument cluster
  6. OPS - Occupant protection system
  7. VSS - Vehicle speed sensor

System Operation

The ground circuit to the Accessory Control Relay is switched by the body control module (BCM) to control the relay when the ignition is turned to accessories or turned on.

When the relay is energized, power is supplied to the radio, windscreen wiper systems and other accessories, if fitted. There are two options for disabling the accessory power

  1. Switching OFF the ignition
  2. Opening the driver door after the ignition is turned OFF

The shut down options can be selected using the MFD or scan tool. The default option is set to Door Open. However, if the radio is switched on after disabling the accessory power, the BCM will energize the Accessory Control Relay for a period of 63 minutes. The Accessory Control Relay is switched off immediately if the radio is switched off within this time frame.

If the intermittent wiper system is in operation after the accessory power is disabled by the BCM, the Accessory Control Relay will be disabled by the BCM when the wiper park signal is sensed. If the wiper park signal is not sensed within 3 seconds, the BCM will automatically disable the relay.