DTC U0100-U0299 HP2

Diagnostic Instructions

DTC Descriptors

DTC U0100 00: Lost Communication With ECM/PCM

DTC U0101 00: Lost Communication With TCM

DTC U0102 00: Lost Communication With Transfer Case Control Module

DTC U0104 00: Lost Communication With Cruise Control Module

DTC U0109 00: Lost Communication With Fuel Pump Control Module

DTC U010F 00: Lost Communication With Air Conditioning Control Module

DTC U0121 00: Lost Communication With Anti-Lock Brake System (ABS) Control Module

DTC U0122 00: Lost Communication With Vehicle Dynamics Control Module

DTC U0125 00: Lost Communication With Multi-axis Acceleration Sensor Module

DTC U0129 00: Lost Communication With Brake System Control Module

DTC U0131 00: Lost Communication With Power Steering Control Module

DTC U0132 00: Lost Communication With Ride Level Control Module

DTC U0137 00: Lost Communication With Trailer Brake Control Module

DTC U0140 00: Lost Communication With Body Control Module

DTC U0141 00: Lost Communication With Body Control Module A

DTC U0146 00: Lost Communication With Gateway "A"

DTC U0151 00: Lost Communication With Restraints Control Module

DTC U0151 71: Lost Communication With Restraints Control Module Invalid Serial Data Received

DTC U0151 7F: Lost Communication With Restraints Control Module Erratic

DTC U0155 00: Lost Communication With Instrument Panel Cluster (IPC) Control Module

DTC U0156 00: Lost Communication With Information Center A (DIC)

DTC U0159 00: Lost Communication With Parking Assist Control Module

DTC U0160 00: Lost Communication With Audible Alert Control Module

DTC U0164 00: Lost Communication With HVAC Control Module

DTC U0165 00: Lost Communication With HVAC Control Module - Rear

DTC U0168 00: Lost Communication With Vehicle Security Control Module

DTC U0170 00: Lost Communication With Restraints System Sensor A (PPS)

DTC U0172 00: Lost Communication With Rollover Sensor

DTC U0184 00: Lost Communication With Radio

DTC U0186 00: Lost Communication With Audio Amplifier

DTC U0194 00: Lost Communication With Digital Radio Receiver (DRR)

DTC U0198 00: Lost Communication With Telematic Control Module

DTC U0199 00: Lost Communication With Door Control Module A (DDM)

DTC U0200 00: Lost Communication With Door Control Module B (PDM)

DTC U0208 00: Lost Communication With Seat Control Module A (DSM/MSM)

DTC U0209 00: Lost Communication With Seat Control Module B (HVSM)

DTC U0210 00: Lost Communication With Seat Control Module C (RHVSM)

DTC U0214 00: Lost Communication With Remote Function Actuation

DTC U0241 00: Lost Communication With Headlamp Control Module A

DTC U0249 00: Lost Communication With Entertainment Control Module - Rear B

DTC U0293 00: Lost Communication With Hybrid Powertrain Control Module

DTC U0298 00: Lost Communication With DC to DC Converter Control Module A

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Module B+	U0100-U0299 *	U0100-U0299 *	--	--
Ignition	U0100-U0299 *	U0100-U0299 *	--	--
Module Ground	U0100-U0299 *	U0100-U0299 *	--	--
Accessory Wake Up Serial Data (circuit 5985)	U1814 *	U0100-U0299 *	--	--
Communication Enable (circuit 5986)	U2099 *	U0100-U0299 *	--	--
Wake Up Signal (circuit 932)	B137B 06 *	U182A *	U189A *	--
Wake Up Signal (circuit 968)	B137A 06 *	U1812 *, U189A in HPCM	3	--
High Speed GMLAN Serial Data (+)	2 *	U0100-U0299*	2 *	--
High Speed GMLAN Serial Data (-)	2 *	U0100-U0299 *	2 *	--
PTLAN (+)	U0074 *	U0100-U0299 *, or U18xx	U0074 *	--
PTLAN (-)	U0074 *	U0100-U0299 *, or U18xx	U0074 *	--
Low Speed GMLAN Serial Data	1 *	U0100-U0299 *	1 *	--
* Multiple U0xxx or U18xx DTCs may be present depending on the location of the open circuit. 1. Scan tool does not communicate with low speed GMLAN device 2. Scan tool does not communicate with high speed GMLAN device 3. Parasitic drain on battery, and will set DTC U1875, U1876, U1878, U1879 as history in the HPCM with the key ON, or as current with the key OFF.

Circuit/System Description

Modules connected to the 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) and the serial data gateway module (SDGM) activate various modules by applying voltage to communication enable and wake up circuits when the ignition key is in ACC, ON or START. Refer to the schematics to determine which modules are activated by each wake up or enable circuit.

Conditions for Running the DTC

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

The modules is never signaled, therefore the specific subsystems will not function.

Conditions for Clearing the DTC

Diagnostic Aids

Reference Information

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

Circuit/System Verification

1. Verify that at least 1 module that communicates on high speed GMLAN serial data communicates with the scan tool.

⇒	If no module communicates on high speed GMLAN serial data, refer to Scan Tool Does Not Communicate with High Speed GMLAN Device.

2. Verify that at least 1 module, excluding BCM and SDGM, that communicates on low speed GMLAN serial data communicates with the scan tool.

⇒	If no module communicates on low speed GMLAN serial data, excluding BCM and SDGM, refer to Scan Tool Does Not Communicate with Low Speed GMLAN Device.

Circuit/System Testing

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

The High Voltage Disabling procedure will perform the following tasks:

•	Identify how to disable high voltage.

•	Identify how to test for the presence of high voltage.

•	Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

Failure to follow the procedures exactly as written may result in serious injury or death.

Important: DTC U0125 may be set in the electronic brake control module (EBCM) due to the multi-axis acceleration sensor module (yaw rate/lateral accelerometer) communicating only on PTLAN serial data if there is a fault on that system. If U0074 or any U18xx exists in any module, diagnose those DTCs prior to DTC U0125.

The multi-axis acceleration sensor module is not indicated on the scan tool as a communicating module. To check for communication on this module check EBCM data parameter Longitudinal Accelerometer Sensor Signal for correct reading.
1. Verify the following DTCs are not present in the modules as follows:

BCM

•

U1814

•

U2099

•

B1428

•

B1370

•

B1380

•

B1440

•

B1441

HPCM

•

U1812

•

U189A

SDGM

•

B137A

•

B137B

•

U0073

•

U0074

•

U182A

•

U209A

⇒	If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

2. Using the Hybrid High Voltage Module Chart below, verify that the non-communicating module is not a high voltage module.

⇒	If the module is a high voltage module, perform the High Voltage Disabling procedure before proceeding with this diagnostic.

3. Reconnect the 12-volt battery.
4. Ignition OFF, disconnect the necessary harness connectors of the non-communicating module.
5. Test for less than 10 ohms between the module ground circuits and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

Important: Not all modules have an enable circuit OR wake up circuit. Refer to the module schematics to identify which modules have these circuits. If the module that is not communicating does not have one of these circuits, proceed to step 6.

6. Ignition ON, verify that a test lamp illuminates between the serial data wake up or communication enable circuit, if equipped, and ground.

⇒	If the test lamp does not illuminate, test the circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the module that supplies voltage to the wake up or enable circuit.

7. Ignition ON, verify that a test lamp illuminates between all B+ 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 module.

8. 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 module.

9. Using the Hybrid High Voltage Module Chart below, verify that the module reporting the DTC is not a high voltage module.

⇒	If the module is a high voltage module, perform the High Voltage Disabling.

10. Reconnect the 12-volt battery.
11. Ignition OFF, disconnect the harness connector containing the serial data circuits between the module that reported the DTC and the module reported as not communicating.
12. Test for less than 1 ohm on the GMLAN serial data circuits between the non-communicating module and the module that displays the DTC.

⇒	If greater than the specified range, test the serial data circuit for open/high resistance.

13. If all circuits test normal, replace the module that is not communicating.

Hybrid High Voltage Module Chart

Module	Voltage System	Data Link Type
Drive Motor Generator Power Inverter Module (PIM) (Includes Drive Motor Control Module (MCM) 1, 2 and Hybrid Powertrain Control Module (HPCM) )	300V 12V	•  High Speed Hybrid GMLAN     •  High Speed GMLAN
Accessory DC Power Control Module (APM)	300V 42V 12V	High Speed Hybrid GMLAN
Transmission Control Module (TCM) (RPO M99)	300V 12V	High Speed GMLAN
Air Conditioning Control Module (ACCM) (Part of AC Compressor with HP2)	300V 12V	Low Speed GMLAN
Drive Motor Generator Battery Control Module (BECM)	300V 12V	High Speed GMLAN
Power Steering Control Module (PSCM)	42V 12V	High Speed LAN

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

DTC U0100-U0299 Except HP2

Diagnostic Instructions

DTC Descriptors

DTC U0100 00: Lost Communication With ECM/PCM

DTC U0101 00: Lost Communication With TCM

DTC U0102 00: Lost Communication With Transfer Case Control Module

DTC U0104 00: Lost Communication With Cruise Control Module

DTC U0109 00: Lost Communication With Fuel Pump Control Module

DTC U0117 00: Lost Communication With Electrical PTO Control Module

DTC U0121 00: Lost Communication With Anti-Lock Brake System (ABS) Control Module

DTC U0122 00: Lost Communication With Vehicle Dynamics Control Module

DTC U0131 00: Lost Communication With Power Steering Control Module

DTC U0132 00: Lost Communication With Ride Level Control Module

DTC U0134 00: Lost Communication With Power Steering Control Module - Rear

DTC U0136 00: Lost Communication With Differential Control Module - Rear

DTC U0140 00: Lost Communication With Body Control Module

DTC U0141 00: Lost Communication With Body Control Module A

DTC U0151 00: Lost Communication With Restraints Control Module

DTC U0151 71: Lost Communication With Restraints Control Module Invalid Serial Data Received

DTC U0151 7F: Lost Communication With Restraints Control Module Erratic

DTC U0155 00: Lost Communication With Instrument Panel Cluster (IPC) Control Module

DTC U0156 00: Lost Communication With Information Center A (DIC)

DTC U0158 00: Lost Communication With Head Up Display

DTC U0159 00: Lost Communication With Parking Assist Control Module

DTC U0160 00: Lost Communication With Audible Alert Control Module

DTC U0164 00: Lost Communication With HVAC Control Module

DTC U0165 00: Lost Communication With HVAC Control Module - Rear

DTC U0168 00: Lost Communication With Vehicle Security Control Module

DTC U0170 00: Lost Communication With Restraints System Sensor A (PPS)

DTC U0172 00: Lost Communication With Rollover Sensor

DTC U0184 00: Lost Communication With Radio

DTC U0186 00: Lost Communication With Audio Amplifier

DTC U0291 00: Lost Communication With Television

DTC U0194 00: Lost Communication With Digital Radio Receiver (DRR)

DTC U0198 00: Lost Communication With Telematic Control Module

DTC U0199 00: Lost Communication With Door Control Module A (DDM)

DTC U0200 00: Lost Communication With Door Control Module B (PDM)

DTC U0208 00: Lost Communication With Seat Control Module A (DSM/MSM)

DTC U0209 00: Lost Communication With Seat Control Module B (HVSM)

DTC U0210 00: Lost Communication With Seat Control Module C (RHVSM)

DTC U0214 00: Lost Communication With Remote Function Actuation

DTC U0230 00: Lost Communication With Rear Gate Module

DTC U0232 00: Lost Communications With Side Object Detection (SOD) Module - Left

DTC U0233 00: Lost Communications With Side Object Detection (SOD) Module - Right

DTC U0236 00: Lost Communications With Column Locking Module (CLM)

DTC U0241 00: Lost Communication With Headlamp Control Module A

DTC U0249 00: Lost Communication With Entertainment Control Module - Rear B

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Module B+	U0100-U0299	U0100-U0299	--	--
Ignition	U0100-U0299	U0100-U0299	--	--
Module Ground	U0100-U0299	U0100-U0299	--	--
Accessory Wake Up Serial Data	U1814	U0100-U0299	--	--
High Speed GMLAN Serial Data Wake Up	U2099	U0100-U0299	--	--
High Speed GMLAN Serial Data (+)	2	U0100-U0299	2	--
High Speed GMLAN Serial Data (-)	2	U0100-U0299	2	--
Low Speed GMLAN Serial Data	1	U0100-U0299	1	--
1. Scan tool does not communicate with low speed GMLAN device 2. Scan tool does not communicate with high speed GMLAN device

Circuit/System Description

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 serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START. Only the modules using high speed GMLAN serial data are connected to the enable or wakeup circuits. To determine which modules are activated using the enable or wakeup circuits refer to Data Communication Schematics.

Conditions for Running the DTC

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

The modules is never signaled, therefore the specific subsystems will not function.

Conditions for Clearing the DTC

Diagnostic Aids

Reference Information

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Data Link Communications Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Verify that following BCM DTCs are not present:

•

U1814

•

U2099

•

B1428

•

B1370

•

B1380

•

B1440

•

B1441

⇒	If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose that DTC prior to this diagnostic.

2. Verify that at least 1 module that communicates on high speed GMLAN serial data communicates with the scan tool.

⇒	If no module communicates on high speed GMLAN serial data, refer to Scan Tool Does Not Communicate with High Speed GMLAN Device.

3. Verify that at least 1 module, excluding BCM, that communicates on low speed GMLAN serial data communicates with the scan tool.

⇒	If no module communicates on low speed GMLAN serial data, excluding BCM, refer to Scan Tool Does Not Communicate with Low Speed GMLAN Device.

Circuit/System Testing

1. Ignition OFF, disconnect the necessary harness connector of the module that is not communicating.
2. Test for less than 1 ohm between the module ground circuits and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

Important: Only the high speed GMLAN modules have a serial data communication enable circuit OR an accessory wakeup serial data circuit, and the BCM is the output for these circuits. Refer to the module schematics to identify which modules have these circuits. If the module that is not communicating is the BCM or does not have one of these circuits, proceed to step 4.

3. Ignition ON, verify that a test lamp illuminates between the serial data communication enable circuit OR the accessory wakeup 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.

4. Ignition ON, verify that a test lamp illuminates between all B+ 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 module.

5. 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 module.

6. Test for less than 1 ohm on the GMLAN serial data circuits between the non-communicating module and the module that displays the DTC.

⇒	If greater than the specified range, test the serial data circuit for open/high resistance.

7. If all circuits test normal, replace the module that is not communicating.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.