Home ReviewsRefund
Home/Chevrolet/Corvette/Chevrolet Corvette C6 (2004-2014)/Repair manual/Communication Devices/Data Communication System
Contents Wiring diagrams Section: Communication Devices All sections

Data Communication System Chevrolet Corvette C6

Communication Devices 8 illustrations ~13487 words

Scheme 1

Scheme 1: Data Communication Schematics
Scheme 1: Data Communication Schematics

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4: Body Control System Schematics
Scheme 4: Body Control System Schematics

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

DIAGNOSTIC CODE INDEX

DTCDescription
DTC B1000B1000 00: Electronic Control Unit (ECU) Performance - No Additional Information B1000 31: Electronic Control Unit (ECU) Performance - General Checksum Error B1000 57: Electronic Control Unit (ECU) Performance - Expected Reaction After Event Did Not Occur
DTC B1001B1001 00: Option Configuration Error B1001 45: Option Configuration Error Variant Not Programmed B1001 46: Option Configuration Error B1001 4B: Option Configuration Error Calibration Not Learned
DTC B1004B1004: Keep Alive Memory (KAM) Reset
DTC B1007B1007: EEPROM Write Error
DTC B1009B1009: EEPROM Checksum Mismatch
DTC B1013B1013: Calibration Read Only Memory (ROM) Checksum Error
DTC B1014B1014: Program Read Only Memory (ROM) Checksum Error
DTC U0001U0001 00: High Speed CAN Communication Bus
DTC U0073 or U2100U0073: Controller Area Network (CAN) Bus Communication U2100: Controller Area Network (CAN) Bus Communication
DTC U0100-U0299** DESCRIPTION NOT COLLECTED **
DTC U1000 and U1255U1000: Class 2 Data Link U1255: Loss of Class 2 Communication
DTC U1001-U1254** DESCRIPTION NOT COLLECTED **
DTC U1300, U1301, or U1305U1300: Class 2 Data Link Low U1301: Class 2 Data Link High U1305: Class 2 Data Link High or Low
DTC U1802U1802: Lost Communication With Fuel Pump Driver Control Module (FPCM) Relay
DTC U2105-U2199U2105 00: Lost Communication With Engine Control System U2106 00: Lost Communication With Transmission Control System U2107 00: Lost Communication With Body Control System U2108 00: Lost Communication With ABS/TCS Control System U2109 00: Lost Communication With Powertrain Control System U2110 00: Lost Communication With Chassis Multiple Control System U2111 00: Lost Communication With Steering Control System U2112 00: Lost Communication With Electronic Suspension Control (ESC) U2113 00: Lost Communication With Sensing and Diagnostic Module (SDM) U2114 00: Lost Communication With PPS or CPS U2115 00: Lost Communication With (Restraints Control System) U2116 00: Lost Communication With Instrument Panel Cluster (IPC) U2117 00: Lost Communication With Driver Information Center (DIC) U2118 00: Lost Communication With Head Up Display (HUD) U2119 00: Lost Communication With Daytime Running Lamps (DRL) System U2120 00: Lost Communication With Automatic Headlamp Leveling Device (AHLD) U2121 00: Lost Communication With Radio Display U2122 00: Lost Communication With Radio U2123 00: Lost Communication With Compact Disc Changer (CDX) U2124 00: Lost Communication With Audio Amplifier U2125 00: Lost Communication With Telematic Unit U2126 00: Lost Communication With (Mobile Communications Control System) U2127 00: Lost Communication With Front HVAC U2128 00: Lost Communication With Rear HVAC U2129 00: Lost Communication With Remote Function Actuator (RFA) U2130 00: Lost Communication With Driver Door Module (DDM) U2131 00: Lost Communication With Driver Seat Module (DSM) U2132 00: Lost Communication With Passenger Door Module (PDM) U2133 00: Lost Communication With Passenger Seat Module (PSM) U2134 00: Lost Communication With Rear Door Module (RDM) U2135 00: Lost Communication With Rear Integration Module (RIM) U2136 00: Lost Communication With Memory Mirror Module (MMM) U2137 00: Lost Communication With Vehicle Theft Deterrent (VTD) U2138 00: Lost Communication With Column Locking Module (CLM) U2139 00: Lost Communication With Column Integration Module (CIM) U2140 00: Lost Communication With Underhood Electrical Center (UEC) U2141 00: Lost Communication With Rear Electrical Center (REC) U2142 00: Lost Communication With Yaw Rate Sensor (YRS) U2143 00: Lost Communication With Steering Angle Sensor (SAS) U2144 00: Lost Communication With Distance Sensing Cruise Control Module U2145 00: Lost Communication With Parking Assistance System (PAS) U2146 00: Lost Communication With Shift Lever Module (SLM) U2147 00: Lost Communication With Auxiliary Heater System (AHS) U2148 00: Lost Communication With Sun Roof Module (SRM) U2149 00: Lost Communication With Tire Pressure Monitor (TPM) System U2150 00: Navigation Electronic Control Unit (ECU) Gateway Communications U2151 00: Navigation Electronic Control Unit (ECU) Communications U2152 00: Navigation Bus Request Line Circuit Low U2153 00: Navigation Electronic Control Unit (ECU) - VICS Communication Circuit U2160 00: Lost Communication With Steering Control System Sensor U2161 00: Lost Communication With Dash Integration Module (DIM) U2162 00: Lost Communication With Instrument Panel integration Module (IPM) U2163 00: Lost Communication With Left Rear Door Module (LRDM) U2164 00: Lost Communication With Right Rear Door Module (RRDM) U2165 00: Lost Communication With Driver Door Switch (DDS) U2166 00: Lost Communication With Driver Position Module (DPM) U2167 00: Lost Communication With Remote Control Door Lock Receiver U2168 00: Lost Communication With Side Object Detection (SOD) Module - Left U2169 00: Lost Communication With Side Object Detection (SOD) Module - Right U2170 00: Lost Communication With Four Wheel Drive (4WD) Clutch U2171 00: Lost Communication With Rear Seat Entertainment (RSE) U2172 00: Lost Communication With Digital Radio Receiver U2173 00: Lost Communication With Passive Entry and Passive Start System U2174 00: Lost Communication With Parking Heater System U2175 00: Lost Communication With Special Vehicle Module U2176 00: Lost Communication With Power Take Off (PTO) Control Module U2177 00: Lost Communication With Cruise Control Module U2178 00: Lost Communication With Trailer Interface Module U2179 00: Lost Communication With Television Module U2180 00: Lost Communication With Folding Top Control Module U2181 00: Lost Communication With Moveable Roof Module

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Data Communications

Begin the system diagnosis with Diagnostic System Check - Vehicle . The Diagnostic System Check - Vehicle will provide the following information

  1. The identification of the control modules which are not communicating.
  2. The identification of any stored diagnostic trouble codes (DTCs) and their status.

The use of the Diagnostic System Check - Vehicle will identify the correct procedures to begin vehicle diagnosis. These must be performed before system DTC or symptom diagnosis.

Control Module U Code List

This list includes all Data Communications related U-code DTCs in alphanumeric order with descriptors for all modules. Not all DTCs listed will be applicable to all vehicles.

DTCDTC Descriptor
U0001 00High Speed CAN Bus Malfunction
U0002 00High Speed CAN Bus
U0010 00CAN BUS Reset Counter Overrun
U0020 00Low Speed CAN Bus
U0073 00Control Module Communication Bus A Off
U0073 71ECU HS Bus Off
U0073 72ECU LS Bus Off
U0074 00Control Module Communication Bus B Off
U0075 00Control Module Communication Bus "C" Off
U0100 00Lost Communication with Engine/Powertrain Control Module (ECM/PCM)
U0100 75Lost Communication with Engine/Powertrain Control Module (ECM)
U0100 7FLost Communication with Engine/Powertrain Control Module (ECM)
U0101 00Lost Communication with Transmission Control Module (TCM)
U0101 75Lost Communication with Transmission Control Module (TCM)
U0102 00Lost Communication with Transfer Case Control Module
U0104 00Lost Communication with Cruise Control Module
U0104 7FLost Communication with Cruise Control Module
U0106 00Lost Communication with Glow Plug Control Module
U0109 00Lost Communication with Fuel Pump Control Module
U010F 00Lost Communication with Air Conditioning Control Module
U0111 00Lost Communication with Battery Energy Control Module
U0115 00Lost Communication with ECM/PCM B
U0117 00Lost Communication Electrical PTO Control Module
U0121 00Lost Communication with Electronic Brake Control Module (EBCM)
U0122 00Lost Communication with Vehicle Stability Control Module
U0123 00Lost Communication with Yaw Rate Sensor Module
U0128 00Lost Communication with Park Brake Control Module
U0129 00Lost Communication with Brake System Control Module
U0131 00Lost Communication with Power Steering Control Module
U0132 00Lost Communication with Ride Level Control Module
U0134 00Lost Communication with Power Steering Control Module - Rear
U0136 00Lost Communication with Differential Control Module - Rear
U0137 00Lost Communication with Trailer Brake Control Module
U0140 00Lost Communication with Body Control Module
U0141 00Lost Communication with Body Control Module A
U0144 00Lost Communication with Body Control Module "D"
U0146 00Lost Communication with Gateway A
U0151 00Lost Communication with Inflatable Restraint Sensing and Diagnostic Module (SDM)
U0151 71Lost Communication with Inflatable Restraint Sensing and Diagnostic Module (SDM) Invalid Serial Data Received
U0151 7FLost Communication with Restraints Control Inflatable Restraint Sensing and Diagnostic Module (SDM) Erratic
U0155 00Lost Communication with Instrument Panel Cluster (IPC) Control Module
U0156 00Lost Communication with Information Center A (DIC)
U0158 00Lost Communication with Head Up Display
U0159 00Lost Communication with Park Assist Module (RPA)
U0160 00Lost Communication with Audible Alert Control Module
U0164 00Lost Communication with HVAC Control Module
U0165 00Loss of Communication with HVAC Control Module - Rear
U0168 00Lost Communication with Vehicle Security Control Module
U0170 00Lost Communication with Restraints System Sensor A (PPS)
U0172 00Lost Communication with Rollover Sensor
U0173 00Lost Communication with "Restraints System Sensor D"
U0181 00Lost Communication with Headlamp Leveling Control Module
U0184 00Lost Communication with Radio
U0186 00Lost Communication with Audio Amplifier
U0191 00Lost Communication with Television
U0194 00Lost Communication with Digital Radio Receiver (DRR)
U0196 00Lost Communication with Rear Audio Control Module
U0198 00Lost Communication with Telematic Control Module
U0199 00Lost Communication with Door Control Module A (DDM)
U0200 00Lost Communication with Door Control Module B (PDM)
U0208 00Lost Communication with Seat Control Module A (DSM/MSM)
U0209 00Lost Communication with Seat Control Module B (HVSM)
U0210 00Lost Communication with Seat Control Module C (RHSM)
U0214 00Lost Communication with Remote Function Actuation
U0230 00Lost Communication with Rear Gate Module
U0232 00Lost Communication with Side Object Detection (SOD) Module - Left
U0233 00Lost Communication with Side Object Detection (SOD) Module - Right
U0236 00Lost Communication with Column Locking Module (CLM)
U023A 00Lost Communication with Vehicle Direction Camera Control Module (Lane Departure Warning)
U0241 00Lost Communication with Headlamp Control Module A
U0249 00Loss of Communication with Entertainment Control Module - Rear B
U0255 00Loss of Communication with Front Display Interface Module
U0256 00Loss of Communication with Front Controls Interface Module
U0257 00Loss of Communication with Front Controls/Display Interface Module
U0293 00Lost Communication with HP2 Powertrain Control Module
U180FControl Module Communication Bus B Off
U1000Class 2 Data Link Malfunction
U1016Lost Communication with ECM/PCM
U1017Lost Communication with Engine Control System
U1024Lost Communication with Transmission Control Module
U1026Lost Communication with Transfer Case Control Module
U1040Lost Communication with Electronic Brake Control Module
U1064Lost Communication with Body Control Module/Dash Integration Module
U1088Lost Communication with Inflatable Restraint Sensing and Diagnostic Module
U1096Lost Communication with Instrument Panel Cluster
U1098Lost Communication with Secondary Information Center
U1099Lost Communication with Head Up Display
U1100Lost Communication with "Driver Information and Displays Control System"
U1128Lost Communication with Radio
U1129Lost Communication with Amplifier
U1133Lost Communication with Mini Disc Changer
U1137Lost Communication with Satellite Digital Audio Reception System (DRR)
U1153Lost Communication with Climate Control Panel
U1164Lost Communication with Driver Door Switch
U1165Lost Communication with Passenger Door Switch
U1176Lost Communication with Remote Function Actuation
U1177Lost Communication with Folding Top Controller
U1193Lost Communication with Remote Control Door Lock Receiver
U1255Loss of Class 2 Communication
U1300Class 2 Data Link Low
U1301Class 2 Data Link high
U1305Class 2 Data Link high or Low
U1500 01Inter-Device Dedicated Bus 1 Short to Battery
U1500 02Inter-Device Dedicated Bus 1 Short to Ground
U1511 00Inter-device Dedicated Bus Lost Communication with Device 1
U1512 00Inter-device Dedicated Bus Lost Communication with Device 2
U1513 00LIN Bus 1 Lost Communication with Device 3
U1650 00Chassis System Dedicated Bus Controller
U1651 00Chassis System Dedicated Bus Sensor
U180F 00Control Module Communication Bus B Off
U1802 00Lost Communication with Fuel Pump Control Module
U1812 00Battery Energy Control Module Bus B High Speed Communication Enable Circuit Low
U1813 00Battery Energy Control Module Bus B High Speed Communication Enable Circuit High
U1814 00Powertrain High Speed Communication Enable Circuit
U1815 00Lost Communication with Drive Motor Control Module A on Bus B
U1816 00Lost Communication with Drive Motor Control Module B on Bus B
U1817 00Lost Communication with Hybrid Powertrain Control Module on Bus B
U1818 00Lost Communication with ECM/PCM A on Bus B
U1820 00Lost Communication with Brake System Control Module on Bus B
U1821 00Lost Communication with DC to DC Converter Control Module A on Bus B
U1822 00Lost Communications with Active Front Steering (AFS) Control Module on Bus B
U1823 00Lost Communications with Antilock Brake System (ABS) Control Module on Bus B
U1824 00Lost Communications with Ride Level Control Module
U1825 00Lost Communications with SCM (CAN)
U1826 71Lost Communication with Multi-Axis Acceleration Sensor Module on Bus "B" Invalid Serial Data Received
U1826 72Lost Communication with Multi-Axis Acceleration Sensor Module on Bus "B" Alive Counter Incorrect/Not Updated
U1826 7FLost Communication with Multi-Axis Acceleration Sensor Module on Bus "B" Erratic
U1827 71Lost Communication with Steering Angle Sensor Module on Bus "B" Invalid Serial Data
U1827 72Lost Communication with Steering Angle Sensor Module on Bus "B" Alive Counter Incorrect/Not Updated
U1827 74Lost Communication with Steering Angle Sensor Module on Bus "B" Value of Signal Protection Calculation Incorrect
U1827 7FLost Communication with Steering Angle Sensor Module on Bus "B" Erratic
U182A 00Lost Communication with Battery Energy Control Module on Bus B
U1842 00Electronic Brake Control Module Lost Communication with Engine Control Module on Bus B
U1843 00Electronic Brake Control Module Lost Communication with Hybrid Engine Control Module on Bus B
U1862 00Battery Energy Control Module Lost Communication with Communications Gateway Module
U1863 00Starter/Generator Control Module Lost Communication with Body Control Module
U1865 00Fuel Operated Heater Lost Communication with Engine Control Module
U1866 00Battery Energy Control Module Lost Communication with Body Control Module
U186A 00Lost Communication with Transfer Case Control Module
U186B 00Lost Communication with TCM
U1875 00Drive Motor A Control Module Lost Communication with Battery Energy Control Module
U1876 00Drive Motor A Control Module Lost Communication with Engine Control Module (ECM)/Powertrain Control Module (PCM)
U1878 00Drive Motor B Control Module Lost Communication with Battery Energy Control Module
U1879 00Drive Motor B Control Module Lost Communication with Engine Control Module (ECM)/Powertrain Control Module (PCM)
U1885 00Battery Energy Control Module Lost Communication with HP2 Powertrain Control Module
U1886 00Battery Energy Control Module Lost Communication with Engine Control Module (ECM)
U1888 00Lost Communication with Battery Pack
U1897 00Starter/Generator Control Module Lost Communication with Battery Energy Control Module
U1899 00Starter/Generator Control Module Lost Communication with Engine Control Module/Powertrain Control Module
U189A 00DC to DC Converter Control Module A Lost Communication with HP2 Powertrain Control Module
U2099 00High Speed Communication Enable Circuit
U209A 00High Speed Communication Enable Circuit Low
U209D 00Battery Energy Control Module High Speed Communication Enable Circuit High
U2100 00Controller Area Network (CAN) Bus Communication
U2100 47Controller Area Network (CAN) Bus Communication
U2102 00Fewer Controllers On Bus Than Programmed
U2103 00Fewer Controllers On Bus Than Programmed
U2105 00Lost Communication with Engine Control Module
U2106 00Lost Communication with Transmission Control Module
U2107 00Lost Communication with Body Control Module
U2108 00Lost Communication with ABS/TCS Control System
U2109 00Lost Communication with Powertrain Control Module
U2110 00Lost Communication with Chassis Multiple Control System
U2111 00Lost Communication with Steering Control Module
U2112 00Lost Communication with Electronic Suspension Control (ESC)
U2113 00Lost Communication with Sensing and Diagnostic Module (SDM)
U2114 00Lost Communication with PPS or CPS
U2115 00Lost Communication with (Restraints Control System)
U2116 00Lost Communication with Instrument Cluster
U2117 00Lost Communication with Info Display
U2118 00Lost Communication with Head Up Display (HUD)
U2119 00Lost Communication with Daytime Running Lamps Control Module
U2120 00Lost Communication with Automatic Headlamp Leveling Control Module
U2121 00Lost Communication with Radio Display
U2122 00Lost Communication with Radio
U2123 00Lost Communication with Compact Disc Changer (CDX)
U2124 00Lost Communication with Audio Amplifier
U2125 00Lost Communication with Telematic Unit
U2126 00Lost Communication with Mobile Communications Control System
U2127 00Lost Communication with Front HVAC Control Module
U2128 00Lost Communication with Rear HVAC Control Module
U2129 00Lost Communication with Remote Function Actuator (RFA)
U2130 00Lost Communication with Driver Door Module (DDM)
U2131 00Lost Communication with Driver Seat Module (DSM)
U2132 00Lost Communication with Passenger Door Module (PDM)
U2133 00Lost Communication with Passenger Seat Module (PSM)
U2134 00Lost Communication with Rear Door Module (RDM)
U2135 00Lost Communication with Rear Integration Module (RIM)
U2136 00Lost Communication with Memory Mirror Module (MMM)
U2137 00Lost Communication with Vehicle Theft Deterrent (VTD)
U2138 00Lost Communication with Column Locking Module (CLM)
U2139 00Lost Communication with Column Integration Module (CIM)
U2140 00Lost Communication with Underhood Electrical Center (UEC)
U2141 00Lost Communication with Rear Electrical Center
U2142 00Lost Communication with Yaw Rate Sensor (YRS)
U2143 00Lost Communication with Steering Angle Sensor (SAS)
U2144 00Lost Communication with Distance Sensing Cruise Control Module
U2145 00Lost Communication with Parking Assistance System (PAS)
U2146 00Lost Communication with Shift Lever Module (SLM)
U2147 00Lost Communication with Auxiliary Heater System (AHS)
U2148 00Lost Communication with Sun Roof Module (SRM)
U2149 00Lost Communication with Tire Pressure Monitor (TPM) System
U2150 00Navigation Electronic Control Unit (ECU) Gateway Communications
U2151 00Navigation Electronic Control Unit (ECU) Communications
U2152 00Navigation Bus Request Line Circuit Low
U2153 00Navigation Electronic Control Unit (ECU) - VICS Communication Circuit
U2160 00Lost Communication with Steering Control System Sensor
U2161 00Lost Communication with Dash Integration Module (DIM)
U2162 00Lost Communication with Instrument Panel integration Module (IPM)
U2163 00Lost Communication with Left Rear Door Module (LRDM)
U2164 00Lost Communication with Right Rear Door Module (RRDM)
U2165 00Lost Communication with Driver Door Switch (DDS)
U2166 00Lost Communication with Driver Position Module (DPM)
U2167 00Lost Communication with Remote Control Door Lock Receiver (RCDLR)
U2168 00Lost Communication with Side Object Detection (SOD) Module - Left
U2169 00Lost Communication with Side Object Detection (SOD) Module - Right
U2170 00Lost Communication with Four Wheel Drive (4WD) Clutch
U2171 00Lost Communication with Rear Seat Entertainment (RSE)
U2172 00Lost Communication with Digital Radio Receiver (DRR)
U2173 00Lost Communication with Passive Entry and Passive Start System
U2174 00Lost Communication with Parking Heater System
U2175 00Lost Communication with Special Vehicle Module
U2176 00Lost Communication with Power Take Off (PTO) Control Module
U2177 00Lost Communication with Cruise Control Module
U2178 00Lost Communication with Trailer Interface Module
U2179 00Lost Communication with Television Module
U2180 00Lost Communication with Folding Top Control Module
U2181 00Lost Communication with Moveable Roof Module

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

The control module runs a program to detect an internal fault when power up is commanded.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

The control module has detected an internal malfunction.

Action Taken When the DTC Sets

The control module refuses all additional inputs.

Conditions for Clearing the DTC

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears in all of the modules except the sensing and diagnostic module (SDM), when the ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
  3. If the code is set in the SDM it will never clear and the Air Bag indicator will remain illuminated.

Reference Information

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for Scan Tool Information

Circuit/System Verification

Verify that DTC B1000 is not set.

  1. If the DTC is set, perform the setup procedure on the control module. If the DTC resets replace the control module.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Some control modules must be configured with serial numbers, vehicle options, or other information. If a control module was not properly configured after installation, that module may set DTC B1001.

Battery voltage is between 9-16 volts and data link communications operate normally.

The control module is not configured properly.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for Scan Tool Information

  1. Verify DTC B1001 is not set. If the DTC is set, program the control module.
  2. With a scan tool, clear the DTCs.
  3. Ignition OFF, remove the scan tool, open and close the drivers door.
  4. Wait 60 seconds, then verify DTC B1001 is not set. If DTC B1001 is set, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The internal fault detection is handled inside the control module.

The control module microprocessor must be active/awake.

The KAM in the control module has been reset. It is a normal occurrence when battery positive voltage or ground is removed from the module, such as a battery disconnect.

The microprocessor reverts back to the base programmed critical operating data until new data is learned and stored in KAM.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for Scan Tool Information

Verify that DTC B1004 is not set.

  1. If the DTC is set, perform the setup procedure on the applicable control module, if the DTC resets replace the module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

As part of normal data processing, the module performs a data programming check. The module writes information to a data block in the electrically erasable read only memory (EEPROM). The module then reads the data and compares it to what was sent to the data block. The EEPROM write error detection is handled inside the control module. No external circuits are involved.

Ignition ON.

Data does not match after 3 consecutive attempts.

The module writes to another area of the EEPROM, this becomes the new permanent area to store the data. The data location is allowed to change until all of the available EEPROM is used.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Refer to Control Module References for scan tool information.

Verify that DTC B1007 is not set.

  1. If the DTC is set, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The electrically erasable programmable read-only memory (EEPROM) check sum error detection is handled inside the control module.

The control module runs the program to detect an EEPROM checksum error after each wake-up. The only requirements are battery positive voltage and ground.

The control module retains an inverse copy of the digital value stored in certain blocks of memory in the EEPROM. The control module then reads the information from those certain blocks and adds the stored inverse value to the current value. If they do not equal 0, the module sets the DTC.

The control module reverts to base operation values programmed for those blocks of data that have failed the check sum test.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the control module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for scan tool information

Verify that DTC B1009 is not set.

  1. If the DTC is set, perform the Restrain ID relearn on the control module. If the DTC resets, replace the applicable control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module runs a program to detect an internal fault when power up is commanded. The module retains a copy of the FLASH application checksum reference value in the FLASH memory. During wake-up the module will compute the FLASH application value and compare it to the FLASH application checksum reference value.

Ignition ON.

FLASH application value does not match checksum reference value.

The module may have limited functional operation depending on the severity of the FLASH calibration corruption.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Refer to Control Module References for scan tool information.

Verify that DTC B1013 is not set.

  1. If the DTC is set, perform the setup procedure on the control module. If the DTC resets replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module runs a program to detect an internal fault when power up is commanded. The module retains a copy of the FLASH application checksum reference value in the FLASH memory. During wake-up the module will compute the FLASH application value and compare it to the FLASH application checksum reference value.

Ignition ON.

FLASH application value does not match checksum reference value.

The control module will enter boot mode, and only the program FLASH memory function will be available.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Refer to Control Module References for scan tool information.

Verify that DTC B1014 is not set.

  1. If the DTC is set, perform the setup procedure on the control module. If the DTC resets replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit Description

Modules connected to the GMLAN serial data circuits monitor for serial data communications on the GMLAN network during normal vehicle operation. Operating information and commands are exchanged among the modules. Each module on GMLAN network maintains a transmit error counter (TEC) and a receive error counter (REC). The counter values increase with detected errors and will decrease with error-free messages. If the TEC value exceeds 255 the controller removes itself from the network and a DTC U0001 will be set.

  1. Voltage supplied to the module is in the normal operating voltage range.
  2. The vehicle power mode requires serial data communication to occur.

A certain number of no valid transmitted messages on the GMLAN serial data circuits are detected by the module.

  1. The module suspends all message transmission.
  2. The module uses default values for all parameters received on the GMLAN serial data circuits.
  3. The module inhibits the setting of all other GMLAN communication DTCs.
  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Diagnostic Aids

  1. This DTC cannot be retrieved with a current status. Diagnosis of current DTC is accomplished via the symptom, Scan Tool Does Not Communicate with GMLAN Device. Refer to «Scan Tool Does Not Communicate with High Speed GMLAN Device»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .
  2. An intermittent condition is likely to be caused by a short on the GMLAN serial data circuits. Use the Scan Tool Does Not Communicate with GMLAN Device procedure in order to isolate an intermittent condition. Refer to «Scan Tool Does Not Communicate with High Speed GMLAN Device»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for scan tool information

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The GMLAN serial data circuits are controller area network (CAN) high and/or low speed serial data buses used to communicate information between the control modules. Typical data transmission speeds must be high enough to ensure that a required real-time response is maintained. There are two different types of GMLAN serial data circuits, the High speed 2-wire circuit and Low speed single wire circuit. The GMLAN serial data circuits also communicate directly to the data link connector (DLC). Messages are interpreted by the externally connected CANdi module which acts as a transceiver for the scan tool.

Modules connected to the GMLAN serial data circuits monitor communications during normal vehicle operation, where operation information is exchanged among the modules. All the modules on the GMLAN networks, maintain a transmit error counter (TEC) and a receive error counter (REC). The counter values increase with detected errors and will decrease with error-free messages.

  1. Supply voltage to the modules are in the normal operating range.
  2. The vehicle is in the RUN power mode.

The module setting the DTC has attempted to establish communications on the GMLAN circuits for more than 7 times.

  1. The module suspends all message transmission.
  2. The module uses default values for all parameters received on the serial data circuits.
  3. The module inhibits the setting of all other communication DTCs.
  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

This DTC cannot be retrieved with a current status. Diagnosis of a current DTC is accomplished via Scan Tool Does Not Communicate with High Speed GMLAN Device . Refer to Data Link References for the correct procedure for the specific module(s) and the busses they use to communicate.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for scan tool information

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Module B+U0100-U0299U0100-U0299
Module IgnitionU0100-U0299U0100-U0299
Module GroundU0100-U0299U0100-U0299
Accessory Wake Up Serial DataU1814U0100-U0299
High Speed GMLAN Serial Data Wake UpU2099U0100-U0299
High Speed GMLAN Serial Data (+)2U0100-U02992
High Speed GMLAN Serial Data (-)2U0100-U02992
Low Speed GMLAN Serial Data1U0100-U02991
1. Scan tool does not communicate with low speed GMLAN device 2. Scan tool does not communicate with high speed GMLAN device

The serial data circuit is the means by which the control modules in the vehicle communicate with each other. Once the scan tool is connected to the serial data circuit through the DLC, the scan tool can be used to monitor each module for diagnostic purposes and to check for diagnostic trouble codes (DTCs). When the ignition switch is in RUN, each control module communicating on the serial data circuit sends a state of health (SOH) message to ensure that the control module is operating properly. When a control module stops communicating on the serial data circuit, for example if the module loses power or ground, the SOH message it normally sends on the serial data circuit disappears. Other control modules on the serial data circuit, which expect to receive that SOH message, detect its absence; those control modules in turn sets a DTC associated with the loss of SOH of the non-communicating control module. The DTC is unique to the control module which is not communicating, for example, when the inflatable restraint sensing and diagnostic module (SDM) SOH message disappears, several modules set DTC U1088. Note: a loss of serial data communications DTC does not represent a failure of the module that set it.

The system voltage is between 9-16 volts.

A supervised periodic message that includes the transmitter module availability has not been received.

Specific subsystems will not function.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
  1. Sometimes, while diagnosing a specific customer concern or after a repair, you may notice a history U-code present. However, there is no associated "current" or "active" status. Loss-of- communication U-codes such as these can set for a variety of reasons. Many times, they are transparent to the vehicle operator and technician, and/or have no associated symptoms. Eventually, they will erase themselves automatically after a number of fault-free ignition cycles. This condition would most likely be attributed to one of these scenarios: A control module on the data communication circuit was disconnected while the communication circuit is awake. Power to one or more modules was interrupted during diagnosis. A low battery condition was present, so some control modules stop communicating when battery voltage drops below a certain threshold. Battery power was restored to the vehicle and control modules on the communication circuit did not all re-initialize at the same time. If a loss-of-communication U-code appears in history for no apparent reason, it is most likely associated with one of the scenarios above. These are all temporary conditions and should never be interpreted as an intermittent fault, causing you to replace a part.
  2. A control module may have a U-code stored in history that does not require any repairs. Issues with late or corrupted messages between control modules can be temporary with no apparent symptom or complaint; this does not mean the control module is faulty. Do not replace a control module based only on a history U-code.
  3. Do not replace a control module reporting a U-code. The U-code identifies which control module needs to be diagnosed for a communication issue.
  4. Communication may be available between the BCM and the scan tool with either the low or high speed GMLAN serial data system inoperative. This condition is due to the BCM using both the low and high speed GMLAN systems.
  5. Use to determine if the module uses high or low speed GMLAN serial data communications.
  6. Some control modules may not have internal protection for specific control circuits and may open a B+ or ignition fuse. If a fuse is open and the B+ or ignition circuit is not shorted to ground, ensure none of the control circuits are shorted to ground before replacing the control module.
  7. This diagnostic can be used for any control module that is not communicating, regardless of the type of serial data circuit it is connected to, providing the vehicle is equipped with the control module.

Schematic Reference

  1. «Data Communication Schematics»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify that following BCM DTCs are not present

  1. U1814
  2. U2099
  3. B1428
  4. B1370
  5. B1380
  6. B1440
  7. B1441 If any listed DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) to diagnose that DTC prior to this diagnostic.

Circuit/System Testing

Note. Use the schematic to identify the following: Control modules the vehicle is equipped with Control module locations on the low and high speed GMLAN serial data circuits The control modules B+, ignition, ground, communication enable and serial data circuit terminals

  1. Determine the module that is not communicating. Refer to «Control Module U Code List»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__control-module-u-code-list) .
  2. Ignition OFF, disconnect the necessary harness connector of the module that is not communicating.
  3. Test for less than 5 ohms between each ground circuit terminal and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.
  5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.
  6. If equipped, ignition ON, verify that a test lamp illuminates between the communication enable circuit terminal OR the accessory wakeup circuit terminal and ground. If the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.
  7. Ignition OFF for 60 seconds, test for less than 5 ohms between the serial data circuit terminals and the DLC terminal listed below: Class 2 serial data circuit terminal 2 Low speed GMLAN serial data terminal 1 High speed GMLAN serial data terminal 6 or 14 If greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module and a module setting the DTC or a serial data splice pack.
  8. If all circuits test normal, replace the control module that is not communicating.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «GMLAN Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for module replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to Voltage
Battery Positive Voltage CircuitsU0100-U0299U0100-U0299
Ignition Voltage CircuitsU0100-U0299U0100-U0299
Module Ground CircuitsU0100-U0299

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for state of health (SOH) monitoring. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. When a module does not associate an identification number with at least one critical parameter within about 5 seconds of beginning serial data communication, DTC U1000 or U1255 is set. If more than one critical parameter does not have an identification number association, the DTC will only be reported once.

  1. Voltage supplied to the module is in the normal operating voltage range of 9-16 volts.
  2. Diagnostic trouble codes U1300, U1301, and U1305 do not have a current status.
  3. The module operation or the vehicle power mode requires serial data communication to occur.

At least one critical operating parameter has not been associated with an identification number within about 5 seconds after beginning serial data communication.

The module uses a default value for the missing parameter.

  1. A current DTC U1000 will clear when all critical operating parameters for the module have been associated with an identification number, or at the end of the current ignition cycle.
  2. A history DTC U1000 will clear after 50 ignition switch ON/OFF cycles with no repeat of the failure.

If a malfunction such as an open fuse to a module occurs while serial data communication is active, a Lost Communication DTC for the specific module is set as a current DTC in other modules. When all serial data communication becomes inactive, the current Lost Communication DTC is cleared, but the history DTC remains. When serial data communication resumes, the module with the open fuse will not be learned by the other modules, so DTC U1000 or U1255 is set as current by the other modules.

In the event of a malfunction occurrence while serial data communication is inactive, DTC U1000 or U1255 is set without a loss of communication DTC for the specific module.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that no DTC within the range of U1001-U1254 exists as current or history in any module. If any DTC within the range of U1001-U1254 does exist, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
  2. Ignition OFF, disconnect the harness connector of the module that is not communicating.
  3. Ignition ON, verify that a test lamp illuminates between all battery positive voltage circuits and ground. If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
  4. Verify that a test lamp illuminates between all ignition voltage circuits and ground. If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
  5. Test for less than 1 ohm between the module ground circuits and ground. If greater than the specified range, test the ground circuit for open/high resistance.
  6. Test for less than 1 ohm in the class 2 serial data circuit(s) between the non-communicating module and the module that displays the DTC. If greater than the specified range, test the serial data circuit(s) for open/high resistance.
  7. If all circuits test normal, replace the module that is not communicating.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «GMLAN Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for module replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Module B+U02105-U2199U02105-U2199
Module IgnitionU02105-U2199U02105-U2199
Module GroundU02105-U2199U02105-U2199
Class 2 Serial Data11, U02105-U21991
1. Scan Tool Does Not Communicate with Class 2 Device

The serial data circuit is the means by which the control modules in the vehicle communicate with each other. Once the scan tool is connected to the serial data circuit through the DLC, the scan tool can be used to monitor each module for diagnostic purposes and to check for diagnostic trouble codes (DTCs). When the ignition switch is in RUN, each control module communicating on the serial data circuit sends a state of health (SOH) message to ensure that the control module is operating properly. When a control module stops communicating on the serial data circuit, for example if the module loses power or ground, the SOH message it normally sends on the serial data circuit disappears. Other control modules on the serial data circuit, which expect to receive that SOH message, detect its absence; those control modules in turn sets a DTC associated with the loss of SOH of the non-communicating control module. The DTC is unique to the control module which is not communicating. Note: a loss of serial data communications DTC does not represent a failure of the module that set it.

The system voltage is between 9-16 volts.

A supervised periodic message that includes the transmitter module availability has not been received.

Specific subsystems will not function.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
  1. Sometimes, while diagnosing a specific customer concern or after a repair, you may notice a history U-code present. However, there is no associated "current" or "active" status. Loss-of- communication U-codes such as these can set for a variety of reasons. Many times, they're transparent to the vehicle operator and technician, and/or have no associated symptoms. Eventually, they will erase themselves automatically after a number of fault-free ignition cycles. This condition would most likely be attributed to one of these scenarios: A control module on the data communication circuit was disconnected while the communication circuit is awake. Power to one or more modules was interrupted during diagnosis. A low battery condition was present, so some control modules stop communicating when battery voltage drops below a certain threshold. Battery power was restored to the vehicle and control modules on the communication circuit did not all re-initialize at the same time. If a loss-of-communication U-code appears in history for no apparent reason, it is most likely associated with one of the scenarios above. These are all temporary conditions and should never be interpreted as an intermittent fault, causing you to replace a part.
  2. A control module may have a U code stored in history that does not require any repairs. Issues with late or corrupted messages between control modules can be temporary with no apparent symptom or complaint; this does not mean the control module is faulty. Do not replace a control module based only on a history U code.
  3. Do not replace a control module reporting a U-code. The U-code identifies which control module needs to be diagnosed for a communication issue.
  4. Use «Data Link References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__data-link-references) to determine if the module uses class 2 serial data communications.
  5. Some control modules may not have internal protection for specific control circuits and may open a B+ or ignition fuse. If a fuse is open and the B+ or ignition circuit is not shorted to ground, ensure none of the control circuits are shorted to ground before replacing the control module.
  6. This diagnostic can be used for any control module that is not communicating, regardless of the type of serial data circuit it is connected to, providing the vehicle is equipped with the control module.

Schematic Reference

  1. «Data Communication Schematics»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Connector End View Reference

  1. «Component Connector End Views»(/chevrolet/corvette/c6-2004-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-electrical-center-id-and-component-and-splice-pack-connector-end-views)
  2. «Splice Pack Connector End Views»(/chevrolet/corvette/c6-2004-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-electrical-center-id-and-component-and-splice-pack-connector-end-views)

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify that following BCM DTCs are not present

  1. U1814
  2. U2099
  3. B1428
  4. B1370
  5. B1380
  6. B1440
  7. B1441 If any listed DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) to diagnose that DTC prior to this diagnostic.

Note. Use the schematic to identify the following: Control modules the vehicle is equipped with Control module locations on the class 2 serial data circuit The control modules B+, ignition, and ground

  1. Determine the module that is not communicating. Refer to «Control Module U Code List»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__control-module-u-code-list) .
  2. Ignition OFF, disconnect the necessary harness connector of the module that is not communicating.
  3. Test for less than 5 ohms between each ground circuit terminal and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. If equipped, verify that a test lamp illuminates between each B+ circuit terminal and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.
  5. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the control module for a short to ground. If the circuits test normal, replace the control module.
  6. Ignition OFF for 60 seconds, test for less than 5 ohms between the serial data circuit terminals and the DLC terminal class 2 serial data terminal 2. If greater than the specified range, test the serial data circuit for an open/high resistance between the non communicating control module and a module setting the DTC or a serial data splice pack.
  7. If all circuits test normal, replace the control module that is not communicating.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «GMLAN Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for module replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to Voltage
Class 2 Serial DataU13001U1301
1. Some modules will set DTC U1305 if they are not capable of distinguishing between a short to battery voltage or ground.

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. In addition to this, Node Alive messages are transmitted by each module on the class 2 serial data circuit about once every 2 seconds. When the module detects high or low voltage on the class 2 serial data circuit for approximately 3 seconds, the setting of all other class 2 serial communication DTCs is inhibited and a DTC will set.

Conditions for Running the DTCs

  1. Voltage supplied to the module is in the normal operating voltage range.
  2. The vehicle power mode requires serial data communication to occur.

Conditions for Setting the DTCs

The class 2 serial data circuit is shorted high or low for approximately 3 seconds.

The module uses a default value for the missing parameter.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
  1. These DTCs cannot be retrieved with a current status. Diagnosis of current DTCs is accomplished via the symptom «Scan Tool Does Not Communicate with Class 2 Device»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .
  2. An intermittent condition is likely to be caused by a short on the class 2 serial data circuit.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen or High ResistanceShort to VoltageSignal Performance
Fuel Pump Control Module Can Bus High Serial DataU1802U1802U1802
Fuel Pump Control Module Can Bus Low Serial DataU1802U1802

The serial data circuits are controller area network (CAN) high and/or low speed serial data buses used to communicate information between the control modules.

The engine is running.

  1. The DTC sets when performing a diagnostic that monitors the state of health of the FPCM relay serial data circuits. The fuel pump control module device failure occurs when the periodic supervisory signal is lost, and no communication with the FPCM over the serial data communication (CAN) circuits.
  2. The above condition is present for greater than 30 milliseconds.

DTCs U1802 are Type A DTCs.

  1. The condition responsible for setting the DTC no longer exists.
  2. A history DTC will clear after 100 malfunction-free ignition cycles have occurred.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Ignition ON, command the fuel pump ON and OFF using the scan tool FPCM output control. The fuel pump should turn ON and OFF.

  1. Ignition OFF, disconnect the X2 harness connector at the FPCM relay, and the harness connector at the FPCM.
  2. Ignition ON, test for less than 1 V between the following terminals listed below and ground. FPCM serial data circuit terminal 40 FPCM serial data circuit terminal 39 If greater than the specified value, test the appropriate serial data circuit for a short to voltage. If the circuit tests normal, replace the FPCM relay.
  3. Ignition OFF, Test for infinite resistance between the following terminals listed below and ground. FPCM serial data circuit terminal 40 FPCM serial data circuit terminal 39 If not the specified value, test the appropriate serial data circuit for a short to ground. If the circuit tests normal, replace the FPCM relay.
  4. Test for less than 2 ohms between the appropriate serial data circuit terminals listed below. Serial data circuit terminal 40 at the FPCM harness connector and terminal 3 at the FPCM relay harness connector. Serial data circuit terminal 39 at the FPCM harness connector and terminal 4 at the FPCM relay harness connector. If greater than the specified value, test the appropriate serial date circuit for an open/high resistance. If the circuit tests normal, replace the FPCM relay.
  5. Test for infinite resistance between the FPCM serial data circuit terminal 40, and the FPCM serial data circuit terminal 39. If not the specified value, repair the serial data circuits for a short together.
  6. If all circuits test normal, replace the FPCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Pump Flow Control Module Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
  2. «Fuel Pump Flow Control Module Relay Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
  3. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for FPCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using the diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Low Speed GMLAN Serial Data1U2105-U21991
Battery Positive Voltage CircuitsU2105-U2199U2105-U2199
Ignition Voltage CircuitsU2105-U2199U2105-U2199
Module Ground CircuitsU2105-U2199U2105-U2199
Accessory Wake Up Serial DataU1814U2105-U2199
High Speed GMLAN Serial Data Wake UpU2099U2105-U2199
1. Scan tool does not communicate with low speed GMLAN device

Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

The body control module (BCM) activates the high speed GMLAN serial data wake up and the accessory wake up serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The high speed GMLAN serial data wake up circuit wakes up the electronic brake control module (EBCM) for bus communication and the accessory wake up serial data circuit wakes up the engine control module (ECM) and transmission control module (TCM).

  1. The system voltage is between 9-16 volts.
  2. The vehicle power mode requires serial data communication to occur.

A supervised periodic message that includes the transmitter module availability has not been received.

The module uses a default value for the missing parameters.

  1. A current DTC clears when the malfunction is no longer present.
  2. A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
  1. Sometimes, while diagnosing a specific customer concern or after a repair, you may notice a history U-code present. However, there is no associated "current" or "active" status. Loss-of- communication U-codes such as these can set for a variety of reasons. Many times, they are transparent to the vehicle operator and technician, and/or have no associated symptoms. Eventually, they will erase themselves automatically after a number of fault-free ignition cycles. This condition would most likely be attributed to one of these scenarios: A control module on the data communication circuit was disconnected while the communication circuit is awake. Power to one or more modules was interrupted during diagnosis. A low battery condition was present, so some control modules stop communicating when battery voltage drops below a certain threshold. Battery power was restored to the vehicle and control modules on the communication circuit did not all re-initialize at the same time. If a loss-of-communication U-code appears in history for no apparent reason, it is most likely associated with one of the scenarios above. These are all temporary conditions and should never be interpreted as an intermittent fault, causing you to replace a part.
  2. A control module may have a U code stored in history that does not require any repairs. Issues with late or corrupted messages between control modules can be temporary with no apparent symptom or complaint; this does not mean the control module is faulty. Do not replace a control module based only on a history U code.
  3. Do not replace a control module reporting a U-code. The U-code identifies which control module needs to be diagnosed for a communication issue.
  4. Communication may be available between the BCM and the scan tool with either the low or high speed GMLAN serial data system inoperative. This condition is due to the BCM using both the low and high speed GMLAN systems.
  5. Use to determine if the module uses high or low speed GMLAN serial data communications.
  6. Some control modules may not have internal protection for specific control circuits and may open a B+ or ignition fuse. If a fuse is open and the B+ or ignition circuit is not shorted to ground, ensure none of the control circuits are shorted to ground before replacing the control module.
  7. This diagnostic can be used for any control module that is not communicating, regardless of the type of serial data circuit it is connected to, providing the vehicle is equipped with the control module.
  1. «Data Communication Schematics»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for scan tool information

IMPORTANTIf more than one module is not communicating use Data Communication Schematics to determine which module is closest to the DLC. Start diagnostics with that module. Terminal and connector identifiers will be different depending on the individual module being tested. Use Schematic Reference and Connector End View Reference to determine which connector and terminal to access.
  1. Using the DTC Descriptor and Diagnostic Aids, determine the module that is not communicating that should be tested.
  2. Ignition OFF, disconnect the harness connector of the module that is not communicating.
  3. Test for less than 2 ohms between the module ground circuits and ground. If greater than specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the high speed GMLAN serial data wake up circuit OR the accessory wake up serial data circuit and ground. If the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuits test normal, replace the BCM.
  5. Ignition ON, verify that a test lamp illuminates between all B+ circuits and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the appropriate module.
  6. Verify that a test lamp illuminates between all ignition voltage circuits and ground. If the test lamp does not illuminate, test the ignition voltage circuits for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the appropriate module.
  7. Test for less than 1 ohm in the GMLAN serial data circuits between the non-communicating module and the module that displays the DTC. If greater than specified range, test the GMLAN serial data circuits for open/high resistance.
  8. If all circuits test normal, replace the module that is not communicating.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «GMLAN Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for module replacement, setup, and programming

Symptoms - Data Communications

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) 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 links.
  2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Data Link Communications Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the systems. Refer to «Checking Aftermarket Accessories»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

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

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. «Scan Tool Does Not Power Up»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  2. «Scan Tool Does Not Communicate with Class 2 Device»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  3. «Scan Tool Does Not Communicate with High Speed GMLAN Device»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The data link connector (DLC) is a standardized 16-cavity connector. Design and location is dictated by an industry-wide standard. The following is required to be provided

  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 scan tool will power up with the ignition OFF. Some modules, however, will not communicate unless the ignition is ON and the power mode master (PMM) module sends the appropriate power mode message.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool References

Control Module References for scan tool information

  1. Ignition OFF, test for less than 5 ohm between terminal 4 at the data link connector (DLC) and ground. If greater than the specified value, test the ground circuit for an open/high resistance.
  2. Ignition OFF, test for less than 5 ohm between the DLC terminal 5 and ground. If greater than the specified value, test the ground circuit for an open/high resistance.
  3. Ignition ON, test for B+ between the DLC terminals 16 and ground. If not the specified value, test the B+ circuit for a short to ground or an open/high resistance.
  4. If all circuits test normal, refer to the scan tool user guide.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Class 2 Serial Data1U1001-U12541
Ground (DLC, terminal 5)1*
* An open in the DLC ground circuit terminal 5 will only effect the communication with the scan tool. The vehicle modules will still communicate. 1. No communication on any class 2 serial data module

The serial data circuit is the means by which the control modules connected to it communicate with each other. Once the scan tool is connected to the class 2 serial data circuit through the DLC, the scan tool can be used to monitor each control module for diagnostic purposes and to check for diagnostic trouble codes (DTCs). Class 2 serial data is transmitted on a single wire at an average of 10.4 Kbps. The bus is active at 7.0 volts nominal and inactive at ground potential. When the ignition switch is in RUN, each control module communicating on the class 2 serial data circuit sends a state of health (SOH) message to ensure that the control module is operating properly. When a control module stops communicating on the class 2 serial data circuit, for example if the control module loses power or ground, the SOH message it normally sends on the data circuit disappears. Other control modules on the class 2 serial data circuit, which expect to receive that SOH message, detect its absence; those control modules in turn set an internal DTC associated with the loss of SOH of the non-communicating control module. The DTC is unique to the control module which is not communicating, for example, when the body control module (BCM) SOH message disappears, several control modules set DTC U1064. Note that a loss of serial data DTC does not normally represent a failure of the control module that set it.

  1. Sometimes, while diagnosing a specific customer concern or after a repair, you may notice a history U-code present. However, there is no associated "current" or "active" status. Loss-of- communication U-codes such as these can set for a variety of reasons. Many times, they're transparent to the vehicle operator and technician, and/or have no associated symptoms. Eventually, they will erase themselves automatically after a number of fault-free ignition cycles. This condition would most likely be attributed to one of these scenarios: A control module on the data communication circuit was disconnected while the communication circuit is awake. Power to one or more modules was interrupted during diagnosis A low battery condition was present, so some control modules stop communicating when battery voltage drops below a certain threshold. Battery power was restored to the vehicle and control modules on the communication circuit did not all re-initialize at the same time. If a loss-of-communication U-code appears in history for no apparent reason, it is most likely associated with one of the scenarios above. These are all temporary conditions and should never be interpreted as an intermittent fault, causing you to replace a part.
  2. Do not replace a control module reporting a U-code. The U-code identifies which control module needs to be diagnosed for a communication issue
  3. An open in the DLC ground circuit terminal 5 will allow the scan tool to operate but not communicate with the vehicle.
  4. An open in the class 2 serial data circuit between the DLC and the BCM will only effect the scan tool communication and will not affect module to module communication.

Schematic Reference

Connector End View Reference

  1. «Component Connector End Views»(/chevrolet/corvette/c6-2004-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-electrical-center-id-and-component-and-splice-pack-connector-end-views)
  2. «Splice Pack Connector End Views»(/chevrolet/corvette/c6-2004-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-electrical-center-id-and-component-and-splice-pack-connector-end-views)

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Note. Use the schematic to identify the following: Control modules the vehicle is equipped with Control module locations on the class 2 serial data circuit The class 2 serial data circuit terminals for each control module.

Testing the Serial Data Circuits for a Short to Voltage

  1. Attempt to communicate with all control modules on the Class 2 serial data circuit, refer to «Data Link References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__data-link-references) . Communications should not be available any control module on the Class 2 serial data circuit. If only one control module is not communicating, diagnose that control module only, refer to «DTC U1001-U1254»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) . If one or more control modules are communicating but not all, refer to «Testing the Serial Data Circuit for an Open/High Resistance»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__testing-the-serial-data-circuit-for) .
  2. Disconnect the scan tool from the DLC. The following tests will be done at the DLC connector.
  3. All access doors closed, ignition OFF for 60 seconds, test for less than 10 ohms between the ground circuit terminal 5 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, test for less than 4.5 V between the serial data circuit terminal 2 and ground. If greater than the specified range, test the serial data circuit for a short to voltage; refer to «Testing the Serial Data Circuits for a Short to Voltage»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__testing-the-serial-data-circuits-for) .
  5. Ignition OFF for 60 seconds, test for greater than 100 ohms between the serial data circuit terminal 2 and ground. If less than the specified range, test the serial data circuit for a short to ground; refer to «Testing the Serial Data Circuits for a Short to Ground»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__testing-the-serial-data-circuits-for) .
  6. Disconnect the harness connector at the JX205 splice pack.
  7. Test for less than 2 ohms between the DLC serial data circuit terminal 2 and the JX205 splice pack terminal A. If greater than the specified range, test the serial data circuit for an open/high resistance. If the circuits test normal, replace the BCM.
  1. Ignition OFF, disconnect the harness connectors at the JX205 and JX208 splice packs.
  2. Ignition ON, test for less than 4.5 V between the DLC serial data circuit terminal 2 and ground. If greater than the specified range, repair the short to voltage.
  3. Test for less than 4.5 V between each serial data circuit at the splice pack connectors and ground. If greater than the specified range, perform the appropriate test listed below
  1. Serial data circuits with one control module, test the serial data circuit for a short to voltage. If the circuit tests normal, replace the control module.
  2. Serial data circuits with 2 or more control modules, test each section of the serial data circuit for a short to voltage. If the circuits test normal, replace the control module that causes the short to voltage when connected.

Testing the Serial Data Circuits for a Short to Ground

  1. Ignition OFF, disconnect the harness connectors at the JX205 and JX208 splice packs.
  2. Test for infinite resistance between the DLC serial data circuit terminal A and ground. If not the specified value, repair the short to ground.
  3. Ignition OFF for 60 seconds, test for greater than 100 ohms between each serial data circuit at the splice pack connectors and ground. If less than the specified range, perform the appropriate test listed below
  1. Serial data circuits with one control module, test the serial data circuit for a short to ground. If the circuit tests normal, replace the control module.
  2. Serial data circuits with 2 or more control modules, test each section of the serial data circuit for a short to voltage. If the circuits test normal, replace the control module that causes the short to ground when connected.

Testing the Serial Data Circuit for an Open/High Resistance

  1. Ignition ON, verify the scan tool communicates with one or more control modules connected to the JX208 splice pack. If all control modules on the JX208 spice pack do not communicate, test the serial data circuit between the JX205 and JX208 splice packs for an open/high resistance. If the circuit tests normal, test each splice pack for an open/high resistance.
  2. Ignition OFF, disconnect one of the harness connectors listed below: JX205 if the control modules not communicating are connected to the JX205 splice pack JX208 if the control modules not communicating are connected to the JX208 splice pack
  3. Install a 3A fused jumper wire between the disconnected splice pack terminal A and a class 2 serial data circuit that is not communicating.
  4. Ignition ON, verify the scan tool communicates with the control modules connected to the class 2 serial data circuit. If any control module does not communicate, test each section of the serial data circuit for an open/high resistance. If the circuits test normal, replace the control module that does not communicate when connected.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for module replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
High Speed GMLAN Serial Data (+)1U0100-U0299*1
High Speed GMLAN Serial Data (-)1U0100-U0299*1
Ground (DLC, terminal 5)1
* No communications with one or more high speed GMLAN modules. An open in only one high speed GMLAN serial data circuit may allow degraded communication between the modules. An open between the data link connector (DLC) and the first splice will only effect the communication with the scan tool. The vehicle modules will still communicate. 1. No communication with any high speed GMLAN module

The serial data is transmitted on two twisted wires that allow speeds up to 500 Kb/s. The twisted pair is terminated with two 120 ohms resistors, one is internal to the engine control module (ECM) and the other can be a separate resistor in a connector assembly or in another control module. The resistors are used as the load for the High Speed GMLAN buss during normal vehicle operation. The high speed GMLAN is a differential bus. The high speed GMLAN serial data bus (+) and high speed GMLAN serial data (-) are driven to opposite extremes from a rest or idle level of approximately 2.5 V. Driving the lines to their extremes, adds one volt to the high speed GMLAN serial data bus (+) circuit and subtracts one volt from the high speed GMLAN serial data bus (-) circuit. If serial data is lost, control modules will set a no communication code against the non-communicating control module. Note that a loss of serial data DTC does not represent a failure of the module that set it.

  1. Sometimes, while diagnosing a specific customer concern or after a repair, you may notice a history U-code present. However, there is no associated "current" or "active" status. Loss-of-communication U-codes such as these can set for a variety of reasons. Many times, they are transparent to the vehicle operator and technician, and/or have no associated symptoms. Eventually, they will erase themselves automatically after a number of fault-free ignition cycles. This condition would most likely be attributed to one of these scenarios: A control module on the data communication circuit was disconnected while the communication circuit is awake. Power to one or more modules was interrupted during diagnosis A low battery condition was present, so some control modules stop communicating when battery voltage drops below a certain threshold. Battery power was restored to the vehicle and control modules on the communication circuit did not all re-initialize at the same time. If a loss-of-communication U-code appears in history for no apparent reason, it is most likely associated with one of the scenarios above. These are all temporary conditions and should never be interpreted as an intermittent fault, causing you to replace a part.
  2. Do not replace a control module reporting a U-code. The U-code identifies which control module needs to be diagnosed for a communication issue.
  3. Communication may be available between the BCM and the scan tool with the high speed GMLAN serial data system inoperative. This condition is due to the BCM using both the high and low speed GMLAN systems.
  4. An open in the DLC ground circuit terminal 5 will allow the scan tool to operate but not communicate with the vehicle. When the scan tool attempts to communicate with the vehicle a message "no CANdi module detected" will be displayed.
  5. The engine will not start when there is a total malfunction of the high speed GMLAN serial data bus.
  6. Technicians may find various Local Area Network (LAN) communication Diagnostic Trouble Codes (DTC) and no low speed GMLAN communications with the scan tool.
  7. The engine will not start when there is a total malfunction of the high speed GMLAN serial data bus. These conditions may be caused by the installation of an aftermarket navigation radio module (see bulletins). Some customers may comment of one or more of the following concerns: Vehicle will not crank. Vehicle cranks but will not start. Vehicle stability enhancement system warning lights and messages. PRNDL gear indicator position errors. Tire Pressure Monitor (TPM) system warning lights.

Schematic Reference

  1. «Data Communication Schematics»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. Each control module may need to be disconnected to isolate a circuit fault. Use the schematic to identify the following: Control modules the vehicle is equipped with High speed GMLAN serial data circuit terminating resistors Control module locations on the high speed GMLAN serial data circuits Each control module's high speed GMLAN serial data circuit terminals

  1. Attempt to communicate with all control modules on the high speed GMLAN serial data circuit, refer to «Data Link References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__data-link-references) . Communications should not be available with two or more control modules on the high speed GMLAN serial data circuit. If only one control module is not communicating, diagnose that control module only; refer to «DTC U0100-U0299»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .
  2. Disconnect the scan tool from the DLC. The following tests will be done at the DLC connector.
  3. All access doors closed, ignition OFF for 60 seconds, test for less than 10 ohms between the ground circuit terminal 5 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, test for less than 4.5 V between the serial data circuits listed below and ground: Terminal 6 Terminal 14 If greater than the specified range, test the serial data circuit for a short to voltage; refer to «Testing the Serial Data Circuits for a Short to Voltage»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .
  5. Ignition OFF for 60 seconds, test for greater than 100 ohms between the serial data circuits listed below and ground: Terminal 6 Terminal 14 If not the specified value, test the serial data circuit for a short to ground; refer to «Testing the Serial Data Circuits for a Short to Ground»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system) .
  6. Test for 50-70 ohms between the serial data circuits terminal 6 and terminal 14. If less than 35 ohms, test for a short between the serial data circuits; refer to «Testing the Serial Data Circuits for a Short between the Circuits»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__testing-the-serial-data-circuits-for) . If 35-50 ohms there may be a third terminating resistor between the serial data circuits. This can happen if the incorrect control module is installed. Some control modules are available with and without the terminating resistors installed to reduce the need of terminating resistors in the wiring harness. If greater than 70 ohms but less than infinite, test the serial data circuit for an open/high resistance; refer to «Testing the Serial Data Circuits for an Open/High Resistance»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#data-communication-system__testing-the-serial-data-circuits-for) . If infinite, test the serial data circuits between the DLC and the first connection to the serial data circuit for an open/high resistance.
  1. Ignition OFF, disconnect the harness connectors with the high speed GMLAN serial data circuits at an easily accessible control module.
  2. Ignition ON, test for greater than 4.5 V between each serial data circuit at the control module connector that was just disconnected and ground. Verify that one or more serial data circuits are greater than 4.5 V. If all serial data circuits are less than the specified range, replace the control module that was disconnected.
  3. Ignition OFF, disconnect the harness connectors with the high speed GMLAN serial data circuits at another control module, in the direction of the circuit shorted to voltage.
  4. Ignition ON, test for greater than 4.5 V between the serial data circuits at the control module connector that was just disconnected and ground. Verify that one or more serial data circuits are greater than 4.5 V. If all serial data circuits are less than the specified range, replace the control module that was just disconnected.
  5. Repeat step 3 until one of the follow conditions are isolated: A short to voltage on the serial data circuit between 2 control modules A short to voltage on the serial data circuit between a control module and a terminating resistor.
  1. Ignition OFF, disconnect the harness connectors with the high speed GMLAN serial data circuits at an easily accessible control module.
  2. Ignition OFF for 60 seconds, test for less than 1k ohms between each serial data circuit at the control module connector that was just disconnected and ground. Verify that one or more serial data circuits are less than 1k ohms. If all serial data circuits are greater than the specified range, replace the control module that was disconnected.
  3. Disconnect the harness connectors with the high speed GMLAN serial data circuits at another control module, in the direction of the circuit shorted to ground.
  4. Ignition OFF for 60 seconds, test for less than 1k ohms between the serial data circuits at the control module connector that was just disconnected and ground. Verify that one or more serial data circuits are less than 1k ohms. If greater than the specified range for all serial data circuits, replace the control module that was just disconnected.
  5. Repeat step 3 until one of the follow conditions are isolated: A short to ground on the serial data circuit between 2 control modules A short to ground on the serial data circuit between a control module and a terminating resistor

Testing the Serial Data Circuits for a Short between the Circuits

  1. Ignition OFF, disconnect the harness connectors with the high speed GMLAN serial data circuits at an easily accessible control module that is not communicating.
  2. Ignition OFF for 60 seconds, test for less than 35 ohms between each pair of serial data circuits at the control module connector that was just disconnected. Verify that one pair of serial data circuits are less than 35 ohms. If each pair of serial data circuits is greater than the specified range, replace the control module that was disconnected.
  3. Connect the harness connectors at the control module that was disconnected.
  4. Disconnect the harness connectors with the high speed GMLAN serial data circuits at another control module, in the direction of the circuits shorted together.
  5. Ignition OFF for 60 seconds, test for less than 35 ohms between each pair of serial data circuits at the control module connector that was just disconnected. Verify that one pair of serial data circuits are less than 35 ohms. If each pair of serial data circuits is within the specified range, replace the control module that was just disconnected.
  6. Repeat step 3 until one of the following conditions are isolated: Serial data circuits shorted together between 2 control modules Serial data circuits shorted together between a control module and a terminating resistor A shorted terminating resistor

Testing the Serial Data Circuits for an Open/High Resistance

  1. Ignition OFF, disconnect the harness connectors with the high speed GMLAN serial data circuits at an easily accessible control module that is not communicating.
  2. Ignition OFF for 60 seconds, test for greater than 100k ohms between each pair of serial data circuits at the control module connector that was just disconnected. Verify that one pair of serial data circuits are greater than 100k ohms. If each pair of serial data circuits is less than the specified range, replace the control module that was disconnected.
  3. Connect the harness connectors at the control module that was disconnected.
  4. Disconnect the harness connectors with the high speed GMLAN serial data circuits at another control module, in the direction of the open circuit.
  5. Ignition OFF for 60 seconds, test for greater than 100k ohms between each pair of serial data circuits at the control module connector that was just disconnected. Verify that one pair of serial data circuits are greater than 100k ohms. If each pair of serial data circuits is less than the specified range, replace the control module that was just disconnected.
  6. Repeat step 3 until one of the following conditions are isolated: An open/high resistance on the serial data circuit between 2 control modules An open/high resistance on the serial data circuit between a control module and a terminating resistor An open/high resistance terminating resistor

Perform the Diagnostic Repair Verification after completing the repair.

  1. «GMLAN Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for control module replacement, setup, and programming

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. The body control module (BCM) emulates some devices that are on high speed GMLAN serial data circuit to the modules on class 2 serial data circuit. The BCM transmits multiple Node Alive messages using source IDs that correspond to each of those high speed GMLAN nodes. This is in addition to the BCM behaving itself as a real node. For the description and operation of these serial data communication circuits refer to Data Link Communications Description and Operation .

IMPORTANTIf the scan tool does not communicate with the vehicle the class two serial data bus must be diagnosed, repaired and functional first in order to prevent misdiagnosis.
Control ModuleData Link TypeDiagnostic Procedure
Schematic Reference: Data Communication Schematics
Adaptive Cruise Control (ACC) Module - XLR onlyHigh Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Adaptive Forward Lighting System (AFS) - XLR onlyHigh Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Audio Amplifier (Amp)Class 2Scan Tool Does Not Communicate with Class 2 Device
Body Control Module (BCM)High Speed GMLAN Class 2Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with Class 2 Device
Digital Radio Receiver (DRR)Class 2Scan Tool Does Not Communicate with Class 2 Device
Driver Door Module (DDM)Class 2Scan Tool Does Not Communicate with Class 2 Device
Driver Door Switch (DDS)Class 2Scan Tool Does Not Communicate with Class 2 Device
Driver Position Module (Memory Seat Module)Class 2Scan Tool Does Not Communicate with Class 2 Device
Electronic Brake Control Module (EBCM)High Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Electronic Suspension Control (ESC or MRRTD) ModuleHigh Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Engine Control Module (ECM)High Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Exhaust Flow Module (EFM, w/Z06 only)Class 2Scan Tool Does Not Communicate with Class 2 Device
Folding Top Controller (FTC, w/convertible top only)Class 2Scan Tool Does Not Communicate with Class 2 Device
Fuel System Control Module (FSCM, w/LS9 engine only)High Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Head Up Display (HUD)Class 2Scan Tool Does Not Communicate with Class 2 Device
HVAC Control ModuleClass 2Scan Tool Does Not Communicate with Class 2 Device
Inflatable Restraint Sensing and Diagnostic Module (SDM)Class 2Scan Tool Does Not Communicate with Class 2 Device
Instrument Panel Cluster (IPC)Class 2Scan Tool Does Not Communicate with Class 2 Device
Passenger Door Module (PDM)Class 2Scan Tool Does Not Communicate with Class 2 Device
RadioClass 2Scan Tool Does Not Communicate with Class 2 Device
Remote Control Door Lock Receiver (RCDLR)Class 2Scan Tool Does Not Communicate with Class 2 Device
Steering Column Lock Control Module (Manual Trans or Europe or Japan markets only)Class 2Scan Tool Does Not Communicate with Class 2 Device
Transmission Control Module (TCM)High Speed GMLANScan Tool Does Not Communicate with High Speed GMLAN Device
Vehicle Communication Interface Module (OnStar® VCIM)High Speed GMLAN - pass through only Class 2Scan Tool Does Not Communicate with Class 2 Device

Removal Procedure

  1. Remove the screws from the data link connector.
  2. Reposition the data link connector from the instrument panel.

Installation Procedure

  1. Position the data link connector to the instrument panel.
  2. Install the screws to the data link connector. Tighten: Tighten the data link connector screws to 2 N.m (18 lb in).
  1. Turn OFF the ignition switch.
  2. Remove the kick-up panel at the right front floor. Refer to «Front Floor Kick-Up Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
  3. Remove 3 retaining screws (1) which secure the body control module (BCM) (2) to the multi-use bracket.
  4. Disconnect the harness connectors from the BCM (2).
  5. Remove the BCM (2) from the vehicle.
  1. Turn OFF the ignition switch.
  2. Connect the harness connectors to the BCM (2).
  3. Position the BCM (2) to the multi-use bracket.
  4. Install 3 retaining screws (1) to the BCM (2) and tighten to 2 N.m (18 lb in).
  5. Install the kick-up panel. Refer to «Front Floor Kick-Up Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
  6. If you are installing a new or replacement BCM, program the BCM to the current vehicle. Refer to «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) .
  1. Remove the door trim panel. Refer to «Front Side Door Trim Panel Replacement - Left Side»(/chevrolet/corvette/c6-2004-2014/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
  2. Remove the window regulator. Refer to «Door Window Regulator Replacement»(/chevrolet/corvette/c6-2004-2014/remont/heated-glassdefoggers/#fixed-and-moveable-window-system) .
  1. Install the window regulator to the door. Refer to «Door Window Regulator Replacement»(/chevrolet/corvette/c6-2004-2014/remont/heated-glassdefoggers/#fixed-and-moveable-window-system) .
  2. Install the door trim panel. Refer to «Front Side Door Trim Panel Replacement - Left Side»(/chevrolet/corvette/c6-2004-2014/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
  3. Refer to «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for programming and setup information.

BCM Overview

The body control module (BCM) is a integrated module that combines functions and features from a normal control module and an body electrical center. There are 4 electrical interfaces that exist between the BCM and the rest of the vehicle. There are 2 connections from the BCM to both the body wiring harness and the instrument panel wiring harness. The BCM contains fuses and relays that are serviceable.

The main features of the BCM are

  1. The BCM is the gateway between class 2 serial data circuit and high speed GMLAN serial data circuit.
  2. The BCM controls multiple functions.
  3. The BCM controls electrical power management.
  4. The BCM is the power mode master.

Gateway

The body control module (BCM) is the gateway between class 2 serial data circuit and high speed GMLAN serial data circuit. The purpose of the gateway is to transfer serial data messages from one sub-net to another.

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 inputs can be

  1. Sensors and switches that are directly connected to the BCM
  2. Class 2 serial data messages received from other vehicle systems connected to the class 2 serial data link
  3. GMLAN serial data messages received from other vehicles systems connected to the high speed GMLAN 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 or high speed GMLAN serial data link. The system capable of performing the required function will respond to the BCM messages.

Some of the other system functions that BCM controls or contributes to are

  1. Exterior lighting control-Refer to «Exterior Lighting Systems Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/exterior-lights/#lighting-systems) .
  2. Interior lighting-Refer to «Interior Lighting Systems Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/exterior-lights/#lighting-systems) .
  3. Automatic door locks-Refer to «Power Door Locks Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/door-locks-anti-theft-systems/#door-lock-system-door-handles) .
  4. Keyless entry-Refer to «Keyless Entry System Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/door-locks-anti-theft-systems/#keyless-entry-system-and-remote-functions) .
  5. Theft deterrent-Refer to «Content Theft Deterrent (CTD) Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/door-locks-anti-theft-systems/#theft-deterrent-system__content-theft-deterrent-ctd-description-and) .
  6. Wipers/washers-Refer to «Wiper/Washer System Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/wiperwasher-systems/#wiper-system-and-washer-system) .
  7. Headlamp washer-Refer to «Headlamp Washer System Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/wiperwasher-systems/#wiper-system-and-washer-system) .
  8. Cruise control-Refer to «Cruise Control Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/cruise-control-systems/#cruise-control-system__cruise-control-description-and-operation) .
  9. Entertainment-Refer to «Radio/Audio System Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system__radioaudio-system-description-and-operation) .
  10. Column lock-Refer to «Steering Wheel and Column Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/steering-column-switches/#steering-wheel-and-steering-column) .
  11. Power roof-Refer to «Power Folding Top Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/sun-rooft-topconvertible-top/#folding-top-system) .

Electrical Load Management

The body control module (BCM) controls electric power management following an idle boost and a load shed algorithm. The load shed control algorithm will deactivate electrical loads if the idle boost algorithm is unable to maintain system voltage. If idle boost is active for a certain amount of time and the system voltage is still below a set value, then load shed will command the heated seats, HVAC blower, and rear defog to deactivate periodically. The deactivations will be cycled such that the customer may not observe limited operation. The duty cycle will be controlled independently by each of heated seats, HVAC blower, and rear defog. If idle boost continues to be active, the engine RPM low, and the system voltage remains low, then load shed will command the heated seats, HVAC blower, and rear defog to deactivate completely. When this occurs, the driver information center (DIC) will display "Battery Saver Active". Once the idle boost becomes unnecessary or the engine RPM is above a set value, and the system voltage is above a set value, the load shed algorithm will command the heated seats, HVAC blower, and rear defog to resume normal operation.

Power Mode

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

The communication among modules is performed through the class 2 and high speed GMLAN serial data circuits. The modules that need real time communication are attached to the high speed GMLAN network. The body control module (BCM) is the gateway between the networks. The purpose of the gateway is to transfer information from one network to another. The gateway will interact with each network according to that network's transmission model. Refer to Body Control System Description and Operation for more information about the gateway.

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

High Speed GMLAN Circuit Description

The data link connector (DLC) allows a scan tool to communicate with the high speed GMLAN serial data circuit. The serial data is transmitted on 2 twisted wires that allow speed up to 500 Kbps. The twisted pair is terminated with two 120 ohms resistors, one is internal to the engine control module (ECM) and the other is internal to the body control module (BCM). The resistors are used to reduce noise on the high speed GMLAN bus during normal vehicle operation. The high speed GMLAN is a differential bus. The high speed GMLAN serial data bus (+) and high speed GMLAN serial data (-) are driven to opposite extremes from a rest or idle level. The idle level which is approximately 2.5 volts is considered a recessive transmitted data and is interpreted as a logic 1. Driving the lines to their extremes adds 1 volt to high speed GMLAN serial data bus (+) and subtracts 1 volt from high speed GMLAN serial data bus (-) wire. This dominant state is interpreted as a logic 0. GMLAN network management supports selective start up and is based on virtual networks. A virtual network is a collection of signals started in response to a vehicle event. The starting of a virtual network signifies that a particular aspect of the vehicle functionality has been requested. A virtual network is supported by virtual devices which represents a collection of signals owned by a single physical device. So, any physical device can have one or more virtual devices. The signal supervision is the process of determining whether an expected signal is being received or not. Failsofting is the ability to substitute a signal with a default value or a default algorithm, in the absence of a valid signal. Some messages are also interpreted as a "heartbeat" of a virtual device. If such a signal is lost, the application will set a no communication code against the respective virtual device. This code is mapped on the Tech 2 screen as a code against the physical device. Note that a loss of serial data DTC does not normally represent a failure of the module that set it.

The interaction between high speed GMLAN and class 2 is assured by BCM, which is the gateway. Any message from the class 2 modules to the high speed GMLAN modules is translated by BCM without carrying the original transmitter ID. Therefore the GMLAN modules consider the BCM as being the originator of all class 2 messages that they receive. The GMLAN serial data communications circuit on this vehicle is in a linear topology. The following modules are connected to the link, in order from DLC to the end of the linear configuration

  1. The body control module (BCM)
  2. The communication interface module (OnStar®)
  3. The electronic suspension control (ESC) module
  4. The transmission control module (TCM)
  5. The electronic brake control module (EBCM)
  6. The engine control module (ECM)

Class 2 Circuit Description

The data link connector (DLC) allows a scan tool to communicate with the class 2 serial data circuit. Class 2 serial data is transmitted on a single wire at an average of 10.4 Kbps. The bus is active at 7 volts nominal and inactive at ground potential. When the ignition switch is in RUN, each module communicating on the class 2 serial data line sends a state of health (SOH) message every 2 seconds to ensure that the module is operating properly. When a module stops communicating on the class 2 serial data line, for example if the module loses power or ground, the SOH message it normally sends on the data line every 2 seconds disappears. Other modules on the class 2 serial data line, which expect to receive that SOH message, detect its absence; those modules in turn set an internal DTC associated with the loss of SOH of the non-communicating module. The DTC is unique to the module which is not communicating, for example, when the body control module (BCM) SOH message disappears, several modules set DTC U1064. Note that a loss of serial data DTC does not normally represent a failure of the module that set it.

The BCM emulates the GMLAN modules on the class 2, embedding the original transmitter ID in GMLAN messages to class 2. Therefore the class 2 modules can set specific non communications DTCs against GMLAN modules.

The class 2 serial data communications circuit on this vehicle is in a star configuration. The star has 2 splice packs, located as follows

  1. The splice pack SP205 is located under the left side of the instrument panel, near the data link connector.
  2. The splice pack SP208 is located under the right side of the instrument panel.

The following modules communicate on the class 2 serial data circuit

  1. The splice pack SP205 attaches to: The driver door module (DDM) The driver door switch (DDS) The driver position module (DPM) The head up display (HUD) The instrument panel cluster (IPC) The inflatable restraint sensing and diagnostic module (SDM) The steering column lock control module (SCLCM)
  2. The splice pack SP208 attaches to: The body control module (BCM) The communication interface module (OnStar®) The digital radio receiver (DRR) The folding top controller (FTC) The HVAC control module The passenger door module (PDM) The radio The remote control lock door receiver (RCDLR)

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Diagnostic Trouble Code (DTC) List - Vehicle
• Engine Controls Schematics (LS3)
• Fuel Pump Flow Control Module Scan Tool Information
• Checking Aftermarket Accessories
• Fastener Caution
• Front Floor Kick-Up Panel Replacement
• Door Window Regulator Replacement
• Exterior Lighting Systems Description and Operation
• Power Door Locks Description and Operation
• Keyless Entry System Description and Operation
• Content Theft Deterrent (CTD) Description and Operation
• Wiper/Washer System Description and Operation
• Cruise Control Description and Operation
• Radio/Audio System Description and Operation
• Steering Wheel and Column Description and Operation
• Power Folding Top Description and Operation
• Power Mode Description and Operation
• DTC B1000
• Data Link References
• Control Module U Code List
• Testing the Serial Data Circuit for an Open/High Resistance
• Testing the Serial Data Circuits for a Short to Voltage

More articles — Accessories & Equipment