Data Communication System: Other Cadillac SRX II facelift

Control Module U Code List

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

For symptom byte information, refer to Symptom Byte List .

Control Module U Code List

Reference Information

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.
2. Verify DTC B1000 is not set. If DTC B1000 is set Replace the device that set the DTC. If DTC B1000 is not set
3. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC B1001 is not set. If DTC B1001 is set Program the device that set the DTC. Verify the DTC does not set. If the DTC sets, replace the device that set the DTC. If the DTC does not set All OK. If DTC B1001 is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC B101D is not set. If DTC B101D is set with symptom byte 43 Program the device that set the DTC. Verify the DTC does not set. If the DTC sets, replace the device that set the DTC. If the DTC does not set All OK. If DTC B101D is set with any symptom byte, except symptom byte 43 Replace the device that set the DTC. If DTC B101D is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC U0028 or U0029 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Verify DTC B101E is not set. If DTC B101E is set Program the device that set the DTC. Verify the DTC does not set. If the DTC sets, replace the device that set the DTC. If the DTC does not set All OK. If DTC B101E is not set
4. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC C056D is not set. If DTC C056D is set in a device that can be programmed Program the device that set the DTC. Verify the DTC does not set. If the DTC sets, replace the device that set the DTC. If the DTC does not set All OK. If DTC C056D is set in a device that cannot be programmed Replace the device that set the DTC. If DTC C056D is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

Data Communication Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool References

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC C056E is not set. If DTC C056E is set Program the device that set the DTC. Verify the DTC does not set. If the DTC sets, replace the device that set the DTC. If the DTC does not set All OK. If DTC C056E is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

Data Communication Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool References

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC P0602 is not set. If DTC P0602 is set Program the device that set the DTC. Verify that the DTC does not set. If the DTC sets, replace the device that set the DTC. If the DTC does not set All OK. If DTC P0602 is not set
3. Verify that DTC P0601, P0603, P0604, P0605, P0606, P060A, P062F, or P262B is not set. If any of the DTCs are set Replace the device that set the DTC. If none of the DTCs are set
4. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

This DTC may not be retrieved with a current status. Diagnosis is accomplished via the symptom, Scan Tool Does Not Communicate with High Speed GMLAN Device. Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device in order to isolate an intermittent condition caused by a short on the GMLAN serial data circuits.

Action Taken When the DTCs Sets

The device uses a default value for the missing parameter.

Diagnosis of this DTC is accomplished via the symptom or an additional DTC. Refer to Scan Tool Does Not Communicate with Low Speed GMLAN Device , or Diagnostic Trouble Code (DTC) List - Vehicle .

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON. Radio ON.
2. Verify DTC U0100-U02FF is set. If the DTC is set Refer to «DTC U0100-U02FF»(ref-644719-S31040985092014072300000) . If the DTC is not set
3. Verify DTC U2098 or DTC U0029 02 is set. If any of the DTCs are set Refer to «DTC U2098»(ref-644719-S11739265112014072300000) . If none of the DTCs are set
4. Verify DTC U0028 is set. If the DTC is set Access the A11 Radio's Last Working MOST ID of Node 1-9 parameters with a scan tool to view MOST device location IDs and MOST bus configuration. Access the A11 Radio's Surrogate MOST Master Node Upstream Position parameter with a scan tool to determine the surrogate MOST Master device and where the MOST ring break occurs. For more information, refer to «Diagnostic Aids»(ref-644719-S28277705432014072300000) section. Refer to Circuit/System Testing (below). If the DTC is not set
5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON. Radio ON.
2. Verify DTC U0028 is set. If the DTC is set Refer to «DTC U0028»(ref-644719-S40976991462014072300000) . If the DTC is not set
3. Verify DTC U0029 is not set with symptom byte 02. If DTC U0029 is set with symptom byte 02 Refer to «DTC U2098»(ref-644719-S11739265112014072300000) . If DTC U0029 is set with other symptom bytes except 02
4. Refer to «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000) to test for an intermittent condition.

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

1. The device suspends all message transmission.
2. The device uses default values for all parameters received on the serial data circuits.
3. In the transmission control module, DTC U0073 will cause the transmission to go into default gears.
4. In the engine control module and transmission control module, DTC U0073 will cause the malfunction indicator lamp (MIL) to illuminate.
5. If equipped with eAssist, DTC U0073 in the hybrid powertrain control module is a type B DTC and will cause the malfunction indicator lamp to illuminate and result in the engine operating in conventional engine mode and will maintain 14 V module operation.
6. The device inhibits the setting of all other communication DTCs.

1. Refer to «Data Link References»(ref-644719-S21036819272014072300000) to determine which serial data communication system is used for a specific device.
2. This DTC may not be retrieved with a current status. Diagnosis is accomplished using the symptom. Refer to «Symptoms - Data Communications»(ref-644719-S37661255242014072300000) .

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify two or more devices are not communicating on the chassis high speed GMLAN serial data circuit. Refer to «Data Link References»(ref-644719-S21036819272014072300000) to determine how many devices should be communicating on the bus. If only one device is not communicating Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S41243632572014072300000) . If two or more devices are not communicating
3. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the scan tool from the X84 Data Link Connector. The following tests will be done at the X84 Data Link Connector. It may take up to 2 minutes for all vehicle systems to power down.
4. Test for less than 10 ohms between the ground circuit terminal 5 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
5. Ignition ON.
6. Test for less than 4.5 V between the serial data circuits listed below and ground: Chassis high speed GMLAN serial data terminal 12 Chassis high speed GMLAN serial data terminal 13 If 4.5 V or greater Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Voltage»(ref-644719-S41243632572014072300000) . If less than 4.5 V
7. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 2 minutes for all vehicle systems to power down.
8. Test for greater than 100 ohms between the serial data circuits listed below and ground: Chassis high speed GMLAN serial data terminal 12 Chassis high speed GMLAN serial data terminal 13 If 100 ohms or less Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Ground»(ref-644719-S41243632572014072300000) . If greater than 100 ohms
9. Test for 50-70 ohms between the serial data circuit terminals 12 and 13: If less than 35 ohms Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S41243632572014072300000) . If between 35-50 ohms There may be a third terminating resistor between the serial data circuits. This can happen if the incorrect device is installed. Some devices are available with and without the terminating resistors installed to reduce the need of terminating resistors in the wiring harness. Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S41243632572014072300000) . If greater than 70 ohms but less than infinite Refer to «Circuit/System Testing - Testing the Serial Data Circuits for an Open/High Resistance»(ref-644719-S41243632572014072300000) . If infinite resistance Repair the open/high resistance in the circuit between the X84 Data Link Connector and the first splice/device in the serial data circuit. If between 50-70 ohms
10. Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S41243632572014072300000) .

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify two or more devices are not communicating on the object detection high speed GMLAN serial data circuit. Refer to «Data Link References»(ref-644719-S21036819272014072300000) to determine how many devices should be communicating on the bus. If only one device is not communicating Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S01240333392014072300000) . If two or more devices are not communicating
3. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 meters (9.8 feet) away from vehicle. Disconnect the scan tool from the X84 data link connector. The following tests will be done at the X84 data link connector. It may take up to 2 minutes for all vehicle systems to power down.
4. Test for less than 10 ohms between the ground circuit terminal 5 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
5. Ignition ON.
6. Test for less than 4.5 V between the serial data circuits listed below and ground: Object detection high speed GMLAN serial data terminal 3 Object detection high speed GMLAN serial data terminal 11 If 4.5 V or greater Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Voltage»(ref-644719-S01240333392014072300000) . If less than 4.5 V
7. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 meters (9.8 feet) away from vehicle. It may take up to 2 minutes for all vehicle systems to power down.
8. Test for greater than 100 ohms between the serial data circuits listed below and ground: Object detection high speed GMLAN serial data terminal 3 Object detection high speed GMLAN serial data terminal 11 If 100 ohms or less Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Ground»(ref-644719-S01240333392014072300000) . If greater than 100 ohms
9. Test for 50-70 ohms between the serial data circuit terminals 3 and 11: If less than 35 ohms Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S01240333392014072300000) . If between 35-50 ohms There may be a third terminating resistor between the serial data circuits. This can happen if the incorrect device is installed. Some devices are available with and without the terminating resistors installed to reduce the need of terminating resistors in the wiring harness. Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S01240333392014072300000) . If greater than 70 ohms but less than infinite Refer to «Circuit/System Testing - Testing the Serial Data Circuits for an Open/High Resistance»(ref-644719-S01240333392014072300000) . If infinite resistance Repair the open/high resistance in the circuit between the X84 data link connector and the first splice/device in the serial data circuit. If between 50-70 ohms
10. Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S01240333392014072300000) .

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC U0077 is not set. If DTC U0077 is set Refer to «Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device»(ref-644719-S33662342712014072300000) . If DTC U0077 is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

1. Ignition ON.
2. Verify DTC U0078 is not set. If DTC U0078 is set Refer to «Scan Tool Does Not Communicate with Low Speed GMLAN Device»(ref-644719-S01386217642014072300000) . If DTC U0078 is not set
3. All OK

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Determine the device that is not communicating. Refer to «Control Module U Code List»(ref-644719-S29829205212014072300000) .
2. Verify that DTC U0073, U2100, U0074, U0078, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Verify that DTC U0125 and DTC U0126 are not set. If both of the DTCs are set together Refer to «Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device»(ref-644719-S33662342712014072300000) . If both of the DTCs are not set together
4. Verify that DTC U0101 5A is not set by K17 Electronic Brake Control Module. If the DTC is set Refer to «DTC C0010»(ref-644739-S11888122122014072300000) . If the DTC is not set
5. Engine running for 10 seconds.
6. Ignition ON, engine OFF, verify that DTC U0100-U02FF is not set. If the DTC U0100-U02FF is set in any device, except the K17 Electronic Brake Control Module Refer to Circuit/System Testing (below). If the DTC U0100-U02FF is set in the K17 Electronic Brake Control Module with any symptom byte, except symptom bytes 71, 72, and 74 Refer to Circuit/System Testing (below). If the DTC U0100-U02FF is set in the K17 Electronic Brake Control Module with symptom byte 71, 72, or 74 along with other DTCs set Diagnose all other DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If the DTC U0100-U02FF is set in the K17 Electronic Brake Control Module with symptom byte 71, 72, or 74 and without other DTCs set Program the K17 Electronic Brake Control Module. Verify the DTC does not set. If the DTC sets, replace the K17 Electronic Brake Control Module. If the DTC does not set All OK. If the DTC U0100-U02FF is not set
7. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC U0300-U0336 is not set. If DTC U0300-U0336 is set Program the device specified by the DTC descriptor. Verify the DTC does not set. If the DTC sets, replace the device specified by the DTC descriptor. If the DTC does not set All OK. If DTC U0300-U0336 is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Engine running for 10 s.
2. Ignition ON, engine OFF, verify DTC U0400-U05FF is not set. If DTC U0400-U05FF is set along with other DTCs set Diagnose all other DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If DTC U0400-U05FF is set without other DTCs set Program the device specified by the DTC descriptor. Verify the DTC does not set. If the DTC sets, replace the appropriate device. If the DTC does not set All OK. If DTC U0400-U05FF is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Determine the LIN device that is not communicating. Refer to «Control Module U Code List»(ref-644719-S29829205212014072300000) .
2. Verify that DTC B1325, B1330, B1370, B1380, B1424, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Verify that DTC U0100-U02FF is not set. If any of the DTCs are set Refer to «DTC U0100-U02FF»(ref-644719-S31040985092014072300000) . If none of the DTCs are set
4. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC U0073, U0074, U0075, U0076, U0077, U0078, U2100, P06E4, P1EB9, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1428, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC U0073, U0078, B1325, B1330, B1370, B1380, B1424, B1428, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC U0073, U0074, U0075, U0076, U0077, U0078, U2100, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1428, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Object Detection Schematics»(ref-644761-S34855061662014072300000)
2. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
3. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Object Detection Description and Operation (with Active Safety System, UGN, N America)»(ref-644761-S11697016882014072300000) , «Object Detection Description and Operation (with Front and Rear Park Assist, UD5)»(ref-644761-S10937575362014072300000) , «Object Detection Description and Operation (with Rear Park Assist, UD7)»(ref-644761-S07076214662014072300000) , «Object Detection Description and Operation (with Side Blind Zone Alert, UFT, N America)»(ref-644761-S16331970222014072300000) , «Object Detection Description and Operation (with Rear Cross Traffic Alert, UFG, N America)»(ref-644761-S02277546972014072300000) , «Object Detection Description and Operation (with Forward Collision Alert, UEU)»(ref-644761-S34349040872014072300000) , «Object Detection Description and Operation (with Lane Departure Warning, UFL)»(ref-644761-S19880672072014072300000) , «Object Detection Description and Operation (with Haptic Signal Motor Seat)»(ref-644761-S41590974642014072300000) , «Object Detection Description and Operation (with Adaptive Cruise Control, KSG, N America)»(ref-644761-S38148261282014072300000) , «Object Detection Description and Operation (with Active Safety System, UGN, except N America)»(ref-644761-S15442867912014072300000) , «Object Detection Description and Operation (with Adaptive Cruise Control, KSG, except N America)»(ref-644761-S11234740752014072300000) , «Object Detection Description and Operation (with Side Blind Zone Alert, UFT, Except N America)»(ref-644761-S03671456892014072300000) , «Object Detection Description and Operation (with Rear Cross Traffic Alert, UFT, Except N America)»(ref-644761-S13193462952014072300000)
2. «Data Link Communications Description and Operation»(ref-644719-S38671377352014072300000)

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTC U0073, U0078, B1325, B1330, B1370, B1380, B1424, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
2. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify DTC U18B9-U18BF is not set. If DTC U18B9-U18BF is set along with other DTCs set Diagnose all other DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If DTC U18B9-U18BF is set without other DTCs set Program the device that set the DTC. Ignition OFF, remove the scan tool, open and close the driver door. Wait 60 s. Verify the DTC does not set. If the DTC sets, replace the appropriate device. If the DTC does not set All OK. If DTC U18B9-U18BF is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify that DTC U0073, U0074, U0075, U0076, U0077, U0078, U2100, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1428, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References

1. Ignition ON.
2. Verify DTC U2101 is not set. If DTC U2101 is set along with other DTCs set Diagnose all other DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If DTC U2101 is set without other DTCs set Program the device that set the DTC. Clear the DTC. Ignition OFF, remove the scan tool, open and close the driver door. Wait 60 s. Verify the DTC does not set. If the DTC sets, replace the appropriate device. If the DTC does not set All OK. If DTC U2101 is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Determine the device that is not communicating. Refer to «Control Module U Code List»(ref-644719-S29829205212014072300000) .
2. Verify that DTC U0073, U2100, U0074, U0078, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
3. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTC U0073, U2100, U1814, U2099, B1325, B1330, B1370, B1380, B1424, B1440, B1441, B1517, C0800, C0899, C12E1, P0560, or P0562 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(ref-644698-S15398667192014072300000) . If none of the DTCs are set
2. Refer to Circuit/System Testing (below).

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Symptoms - Data Communications

Note. The following steps must be completed before using the symptom tables.

1. Perform the «Diagnostic System Check - Vehicle»(ref-644698-S03753758692014072300000) before using the symptom tables in order to verify that all of the following are true: There are no Diagnostic Trouble Codes (DTC) set. The devices 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»(ref-644719-S38671377352014072300000) .

Intermittent

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

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify two or more devices are not communicating on the chassis high speed GMLAN serial data circuit. Refer to «Data Link References»(ref-644719-S21036819272014072300000) to determine how many devices should be communicating on the bus. If only one device is not communicating Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S32985232982014072300000) . If two or more devices are not communicating
3. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the scan tool from the X84 Data Link Connector. The following tests will be done at the X84 Data Link Connector. It may take up to 2 minutes for all vehicle systems to power down.
4. Test for less than 10 ohms between the ground circuit terminal 5 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
5. Ignition ON.
6. Test for less than 4.5 V between the serial data circuits listed below and ground. Terminal 12 Terminal 13 If 4.5 V or greater Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Voltage»(ref-644719-S32985232982014072300000) . If less than 4.5 V
7. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 2 minutes for all vehicle systems to power down.
8. Test for greater than 100 ohms between the serial data circuits listed below and ground. Terminal 12 Terminal 13 If 100 ohms or less Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Ground»(ref-644719-S32985232982014072300000) . If greater than 100 ohms
9. Test for 50-70 ohms between the serial data circuit terminals 12 and 13. If less than 35 ohms Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S32985232982014072300000) . If between 35-50 ohms There may be a third terminating resistor between the serial data circuits. This can happen if the incorrect device is installed. Some devices are available with and without the terminating resistors installed to reduce the need of terminating resistors in the wiring harness. Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S32985232982014072300000) . If greater than 70 ohms but less than infinite Refer to «Circuit/System Testing - Testing the Serial Data Circuits for an Open/High Resistance»(ref-644719-S32985232982014072300000) . If infinite resistance Repair the open/high resistance in the circuit between the X84 Data Link Connector and the first splice/device in the serial data circuit. If between 50-70 ohms
10. Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S32985232982014072300000) .

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON.
2. Verify two or more devices are not communicating on the high speed GMLAN serial data circuit. Refer to «Data Link References»(ref-644719-S21036819272014072300000) to determine how many devices should be communicating on the bus. If only one device is not communicating Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S36666245692014072300000) . If two or more devices are not communicating
3. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 meters (9.8 feet) away from vehicle. Disconnect the scan tool from the X84 data link connector. The following tests will be done at the X84 data link connector. It may take up to 2 minutes for all vehicle systems to power down.
4. Test for less than 10 ohms between the ground circuit terminal 5 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
5. Ignition ON.
6. Test for less than 4.5 V between the serial data circuits listed below and ground. Terminal 6 Terminal 14 If 4.5 V or greater Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Voltage»(ref-644719-S36666245692014072300000) . If less than 4.5 V
7. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 meters (9.8 feet) away from vehicle. It may take up to 2 minutes for all vehicle systems to power down.
8. Test for greater than 100 ohms between the serial data circuits listed below and ground. Terminal 6 Terminal 14 If 100 ohms or less Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Ground»(ref-644719-S36666245692014072300000) . If greater than 100 ohms
9. Test for 50-70 ohms between the serial data circuit terminals 6 and 14. If less than 35 ohms Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S36666245692014072300000) . If between 35-50 ohms There may be a third terminating resistor between the serial data circuits. This can happen if the incorrect device is installed. Some devices are available with and without the terminating resistors installed to reduce the need of terminating resistors in the wiring harness. Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short between the Circuits»(ref-644719-S36666245692014072300000) . If greater than 70 ohms but less than infinite Refer to «Circuit/System Testing - Testing the Serial Data Circuits for an Open/High Resistance»(ref-644719-S36666245692014072300000) . If infinite resistance Repair the open/high resistance in the circuit between the X84 data link connector and the first splice/device in the serial data circuit. If between 50-70 ohms
10. Refer to «Circuit/System Testing - Testing the Device Circuits»(ref-644719-S36666245692014072300000) .

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Schematic Reference

1. «Data Communication Schematics»(ref-644719-S20740415782014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

1. «Circuit Testing»(ref-644726-S12298670162014072300000)
2. «Connector Repairs»(ref-644726-S09053351542014072300000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-644726-S21103124652014072300000)
4. «Wiring Repairs»(ref-644726-S20665353652014072300000)

Scan Tool Reference

Control Module References for scan tool information

Note. Use the schematic to identify the following: Devices the vehicle is equipped with Device and splice pack locations on the low speed GMLAN serial data circuit The low speed GMLAN serial data circuit terminals for each device or splice pack

1. Attempt to communicate with all devices on the low speed GMLAN serial data circuit. Refer to «Data Link References»(ref-644719-S21036819272014072300000) .
2. Verify which devices are communicating on the low speed GMLAN serial data circuit. If only one device is not communicating Diagnose that device only. Refer to «DTC U0100-U02FF»(ref-644719-S31040985092014072300000) . If one or more devices are communicating but not all Refer to «Circuit/System Testing - Testing the Serial Data Circuit for an Open/High Resistance»(ref-644719-S31214056452014072300000) . If none of the devices are communicating
3. Ignition OFF, all access doors closed, all vehicle systems OFF, all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the scan tool from the X84 Data Link Connector. The following tests will be done at the X84 Data Link Connector. It may take up to 2 minutes for all vehicle systems to power down.
4. Test for less than 10 ohms between the ground circuit terminal 5 and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
5. Ignition ON.
6. Test for less than 4.5 V between the serial data circuit terminal 1 and ground. If 4.5 V or greater Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Voltage»(ref-644719-S31214056452014072300000) . If less than 4.5 V
7. Ignition OFF, all access doors closed, all vehicle systems OFF, all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 2 minutes for all vehicle systems to power down.
8. Test for greater than 100 ohms between the serial data circuit terminal 1 and ground. If 100 ohms or less Refer to «Circuit/System Testing - Testing the Serial Data Circuits for a Short to Ground»(ref-644719-S31214056452014072300000) . If greater than 100 ohms
9. Disconnect the appropriate harness connector at the first splice pack closest in the circuit to the X84 Data Link Connector.
10. Test for less than 2 ohms between the X84 Data Link Connector's serial data circuit terminal 1 and the splice pack harness connector's serial data input terminal. If 2 ohms or greater Repair the open/high resistance in the serial data circuit. If less than 2 ohms
11. Replace the splice pack.

Perform the Diagnostic Repair Verification after completing the repair.

1. «GMLAN and Media Oriented Systems Transport (MOST) Wiring Repairs»(ref-644745-S15080437002014072300000)
2. «Control Module References»(ref-644727-S14842497662014072300000) for device replacement, programming and setup

Data Link References

This table identifies which serial data link that a particular device uses for in-vehicle data transmission. Some devices may use more than one data link to communicate. Some devices 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. Not all devices listed will be applicable to all vehicles. Refer to the schematics to determine which devices apply. For the description and operation of these serial data communication circuits, refer to Data Link Communications Description and Operation .

Data Link References

Scheme 13

Body Control Module Replacement

Scheme 14

Body Control Module Bracket Replacement

Power Mode Master

This vehicle body control module (BCM) functions as the power mode master (PMM). The ignition switch is a low current switch with multiple discrete ignition switch signals to the PMM for determining the power mode that will be sent over the serial data circuits to the other modules that need this information; the PMM will activate relays and other direct outputs of the PMM as needed. Refer to Power Mode Description and Operation for a complete description of power mode functions.

Gateway

The body control module (BCM) in this vehicle functions as a gateway or translator. The purpose of the gateway is to translate serial data messages between the GMLAN high speed bus and the GMLAN low speed bus for communication between the various modules. The gateway will interact with each network according to that network's transmission protocol.

All communication between the BCM and a scan tool is on the high speed GMLAN serial data circuits. A lost communication DTC typically is set in modules other than the module with a communication failure.

Body Control

The various body control module (BCM) input and output circuits are illustrated in the corresponding functional areas on the BCM electrical schematics. Refer to the Body Control System Schematics for more detailed information.

Data Link Connector (DLC)

The X84 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. Terminal 1 Low speed GMLAN communications terminal
2. Terminal 2 Class 2 communications terminal
3. Terminal 3 Mid speed GMLAN serial bus (+) terminal or Object high speed GMLAN serial bus (+) terminal
4. Terminal 4 Scan tool power ground terminal
5. Terminal 5 Common signal ground terminal
6. Terminal 6 High speed GMLAN serial data bus (+) terminal
7. Terminal 7 Keyword communications terminal
8. Terminal 11 Mid speed GMLAN serial bus (-) terminal or Object high speed GMLAN serial bus (-) terminal
9. Terminal 12 Chassis high speed GMLAN serial bus (+) terminal
10. Terminal 13 Chassis high speed GMLAN serial bus (-) terminal
11. Terminal 14 High speed GMLAN serial data bus (-) terminal
12. Terminal 16 Scan tool power, battery positive voltage terminal

Serial Data Reference

The scan tool communicates over the various buses on the vehicle. When a scan tool is installed on a vehicle, the scan tool will try to communicate with every device that could be optioned into the vehicle. If an option is not installed on the vehicle, the scan tool will display No Comm (or Not Connected) for that optional device. In order to avert misdiagnoses of No Communication with a specific device, refer to Data Link References for a list of devices, the buses they communicate with, and the RPO codes for a specific device.