Data Link Communications Schematic Icons
Data Link Communications Schematic Icons Icon Icon Definition CAUTION: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling Zones. Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs
Scheme 1
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
| Callout | Component Name |
|---|---|
| 1 | I/P Harness Connector |
| 2 | Body Control Module (BCM) Connectors |
| 3 | Splice Pack SP205 |
| 4 | Fuse Block - Left I/P |
| 5 | Data Link Connector (DLC) |
| 6 | I/P Courtesy Lamp - Left |
| 7 | I/P Courtesy Lamp Connector - Left |
| 8 | Instrument Panel |
| 9 | Left Windshield Pillar |
Scheme 8
| Callout | Component Name |
|---|---|
| 1 | I/P Harness Connector |
| 2 | I/P Harness |
| 3 | Splice Pack - SP205 |
| 4 | I/P Courtesy Lamp - Left |
| 5 | Fuse Block - Left I/P |
Scheme 9
| Callout | Component Name |
|---|---|
| 1 | Splice Pack SP207 |
| 2 | Relay Block - I/P |
| 3 | I/P Extension Harness |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 1: A total loss of communication on CAN serial data link should be diagnosed first.
- 8: The modules which can communicate indicate the module which cannot communicate. You must clear the DTC from these modules to avoid future misdiagnosis.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
| 1 | Install a scan tool. Start the engine. Retrieve DTCs from the engine control module (ECM). Is DTC U0073 set as current? | Go to DTC U0073 | Go to Step 2 |
| 2 | IMPORTANT: Use the DTC list from DTC Descriptors in order to determine which module is not communicating on the controller area network (CAN) serial data bus. Turn the ignition ON, with the engine OFF. Test the following circuits of the module that is not communicating on the CAN serial data bus for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 7 | Go to Step 3 |
| 3 | Turn OFF the ignition. Test the ground circuits of the module that is not communicating on the CAN serial data bus for an open. Refer to the following procedures: Control Module References in Body Control System for the applicable Schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 7 | Go to Step 4 |
| 4 | Test the CAN serial data circuits of the module that is not communicating on the CAN serial data bus for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 5 |
| 5 | Inspect the harness connectors of the module that is not communicating on the CAN serial data bus for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The CAN serial data circuits Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems | Go to Step 7 | Go to Step 6 |
| 6 | IMPORTANT: Perform the programming or set up procedure for the module, if required. Replace the module that is not communicating on the CAN serial data bus. Refer to Control Module References for the applicable replacement procedure.Did you complete the replacement? | Go to Step 7 | |
| 7 | Select the Display DTCs function for the modules which had the Loss of Communications DTC set. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References in Body Control System | Go to Step 8 |
| 8 | Use the scan tool in order to clear the DTCs. Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared. Did you complete the action? | Go to Control Module References in Body Control System | |
| IMPORTANT |
|---|
| Use the DTC list from DTC Descriptors in order to determine which module is not communicating on the controller area network (CAN) serial data bus. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the module, if required. |
DTC U0100-U0299 (Diesel Engine)
The number below refers to the step number on the diagnostic table.
- 12: The module which was not communicating may have set Loss of Communication DTCs for those modules that it was monitoring.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List and Inline Harness Connector End Views in Wiring Systems | |||
| 1 | Turn ON the ignition, with the engine OFF. Install the scan tool with the CANdi module attached to it. Attempt to communicate with the following modules: The energy storage control module (ESCM) The starter/generator control module (SGCM) The elctro-hydraulic power steering (EHPS) module Does the scan tool communicate with any of the listed modules? | Go to Step 7 | Go to Step 2 |
| 2 | IMPORTANT: Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions. Test the high speed GMLAN serial data circuits at the data link connector (DLC) for the following conditions: A short to ground A short to voltage A short between high speed GMLAN (+) and GMLAN (-) circuits Refer to the following in Wiring Systems: Testing for Intermittent Conditions and Poor Connections Circuit Testing Did you find any of the above conditions? | Go to Step 3 | Go to Step 7 |
| 3 | Repeat the following steps on high speed GMLAN serial data circuits until the short found in the previous step at the DLC connector disappears, or until all modules are disconnected. Disconnect the high speed GMLAN modules, one at a time, in the following order: The powertrain control module (PCM) The hybrid control module (HCM) The EHPS The SGCM The ESCM Test the high speed GMLAN serial data circuits at the DLC connector for the short found at step 2. Does the short found at step 2 at the DLC sill exist? | Go to Step 6 | Go to Step 4 |
| 4 | IMPORTANT: If only the PCM was disconnected on step 3, answer No at this step. Test the high speed GMLAN serial data circuits between the last 2 disconnected modules for the short found at step 2.Did you find and correct the condition? | Go to Step 12 | Go to Step 5 |
| 5 | Consider the last disconnected module as the non communicating module for the following steps. | Go to Step 10 | |
| 6 | Repair the high speed GMLAN serial data circuits between the DLC and the ESCM/SGCM for the short found in step 2. Refer to the following in Wiring Systems: Connector Repairs Wiring Repairs Did you complete the repair? | Go to Step 12 | |
| 7 | IMPORTANT: Use the DTC Descriptors list in order to determine which module is not communicating. If multiple DTCs were set, consider the closest module to the PCM as the non-communicating module. Test the following circuits of the module that is not communicating for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 12 | Go to Step 8 |
| 8 | Turn OFF the ignition. Test the ground circuits of the module that is not communicating for an open. Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 12 | Go to Step 9 |
| 9 | Test the high speed GMLAN serial data circuits of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 10 |
| 10 | Inspect the harness connectors of the module that is not communicating for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The high speed GMLAN serial data circuits Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 12 | Go to Step 11 |
| 11 | IMPORTANT: Perform the programming or set up procedure for the module, if required. Replace the module that is not communicating. Refer to Control Module References in Body Control System for the applicable replacement procedure.Did you complete the replacement? | Go to Step 12 | |
| 12 | Reconnect all disconnected components, if applicable. Install a scan tool. Turn ON the ignition, with the engine OFF. Select the Display DTCs function for the module which was not communicating. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 13 |
| 13 | Select the Display DTCs function for the modules which had the Loss of Communications DTC set. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 14 |
| 14 | Use the scan tool in order to clear the DTCs. Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared. Did you complete the action? | Go to Control Module References for the applicable Diagnostic System Check | |
| IMPORTANT |
|---|
| Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions. |
| IMPORTANT |
|---|
| If only the PCM was disconnected on step 3, answer No at this step. |
| IMPORTANT |
|---|
| Use the DTC Descriptors list in order to determine which module is not communicating. If multiple DTCs were set, consider the closest module to the PCM as the non-communicating module. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the module, if required. |
DTC U0100-U0299 (HP2)
The numbers below refer to the step numbers on the diagnostic table.
- 1: A DTC U1001-U1254 Lost Communications with XXX with a history status may indicate the cause of U1000.
- 2: The modules not communicating are the likely cause of U1000. The modules that are available on the class 2 serial data circuit are listed in the Circuit Description.
- 6: The module which was not communicating due to a poor connection to the class 2 serial data circuit may have set DTC U1001-U1254 Lost Communications with XXX for those modules that it was monitoring.
- 9: The modules which can communicate indicate the module which cannot communicate. You must clear the serial data communication DTCs from these modules to avoid future misdiagnosis.
- 12: If all modules are communicating, the module which set U1000 may have done so due to some other condition.
- 14: The module which set U1000 is the likely cause of the malfunction.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List and Inline Harness Connector End Views in Wiring Systems | |||
| 1 | Install a scan tool. Turn ON the ignition, with the engine OFF. Record the DTCs set in by each module. If using a Tech 2, use the Class 2 DTC Check feature to determine which modules have DTCs set. Did you record any DTCs in the range of U1001-U1254 with a history status? | Go to Diagnostic Trouble Code (DTC) List | Go to Step 2 |
| 2 | Turn ON the ignition, with the engine OFF. Attempt to communicate with each module on the class 2 serial data circuit. If using a Tech 2, obtain this information using the class 2 Message Monitor feature. Record all of the modules communicating on the class 2 serial data circuit. Compare the list of modules which are communicating to the list given in Circuit Description. Does any module on the class 2 serial data circuit not communicate? | Go to Step 3 | Go to Step 12 |
| 3 | Test the following circuits of the module that is not communicating for an open or short to ground: The battery positive voltage supply circuits The switched battery positive supply circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits Refer to the following: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 4 |
| 4 | Turn OFF the ignition. Test the ground circuits of the module that is not communicating for an open. Refer to the following: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 5 |
| 5 | IMPORTANT: Inspect all connectors in the serial data communications circuit. Refer to the following: Data Link Connector (DLC) Schematics Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems Turn OFF the ignition. Test the class 2 serial data circuits of the module that is not communicating for an open. Refer to the following: Data Link Connector (DLC) Schematics Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 6 |
| 6 | Inspect the harness connector of the module that is not communicating for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The switched battery positive voltage supply The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The ground circuits The class 2 serial data circuits Refer to the following: Control Module References in Body Control System for the applicable schematic Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 7 |
| 7 | IMPORTANT: Perform the module programming or setup procedure if required. Replace the module that is not communicating. Refer to Control Module References in Body Control System for the appropriate Repair Instructions for the module replacement.Did you complete the replacement? | Go to Step 10 | |
| 8 | Install a scan tool. Turn ON the ignition, with the engine OFF. Select the Display DTCs function for the module which was not communicating. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References in Body Control System for applicable Diagnostic System Check | Go to Step 9 |
| 9 | Use the scan tool in order to clear the DTCs. Did you complete the action? | Go to Step 10 | |
| 10 | Select the Display DTCs function for the modules which had U1000 set as a current DTC. Does the scan tool display DTCs which do not begin with a "U"? | Go to Control Module References in Body Control System for applicable Diagnostic System Check | Go to Step 11 |
| 11 | Use the scan tool in order to clear the DTCs. Did you complete the action? | System OK | |
| 12 | Did you record any other DTCs for the modules which had U1000 set as a current DTC? | Go to Control Module References in Body Control System for applicable Diagnostic System Check | Go to Step 13 |
| 13 | Install a scan tool. Turn ON the ignition, with the engine OFF. Use the scan tool in order to clear the DTCs. Turn OFF the ignition for at least 5 seconds. Turn ON the ignition with the engine OFF. Select the Display DTCs function. Does the scan tool display U1000 set as a current DTC? | Go to Step 14 | Go to Diagnostic Aids |
| 14 | IMPORTANT: Perform the module programming or setup procedure if required. Replace the module which had U1000 set as a current DTC. Refer to Control Module References in Body Control System for the appropriate Repair Instructions for the module replacement.Did you complete the replacement? | System OK | |
| IMPORTANT |
|---|
| Inspect all connectors in the serial data communications circuit. Refer to the following: Data Link Connector (DLC) Schematics Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems |
| IMPORTANT |
|---|
| Perform the module programming or setup procedure if required. |
| IMPORTANT |
|---|
| Perform the module programming or setup procedure if required. |
DTC U1000
The number below refers to the step number on the diagnostic table.
- 6: The module which was not communicating on the class 2 serial data circuit may have set Loss of Communication DTCs for those modules that it was monitoring.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List and Inline Harness Connector End Views in Wiring Systems | |||
| 1 | IMPORTANT: Use the control module ID number list in order to determine which module is not communicating. Test the following circuits of the module that is not communicating for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 6 | Go to Step 2 |
| 2 | Turn OFF the ignition. Test the ground circuits of the module that is not communicating for an open. Refer to the following: Control Module References in Body Control System for the applicable Schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 6 | Go to Step 3 |
| 3 | Test the class 2 serial data circuits of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 6 | Go to Step 4 |
| 4 | Inspect the harness connectors of the module that is not communicating for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The class 2 serial data circuits Refer to the following: Control Module References in Body Control System for the applicable schematic Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
| 5 | IMPORTANT: Perform the programming or set up procedure for the module, if required. Replace the module that is not communicating. Refer to Control Module References for the applicable replacement procedure.Did you complete the replacement? | Go to Step 6 | |
| 6 | Install a scan tool. Turn ON the ignition with the engine OFF. Select the Display DTCs function for the module which was not communicating. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 7 |
| 7 | Select the Display DTCs function for the modules which had the Loss of Communications DTC set. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 8 |
| 8 | Use the scan tool in order to clear the DTCs. Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared. Did you complete the action? | Go to Control Module References for the applicable Diagnostic System Check | |
| IMPORTANT |
|---|
| Use the control module ID number list in order to determine which module is not communicating. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the module, if required. |
DTC U1001-U1254
The numbers below refer to the step numbers on the diagnostic table.
- 1: A total loss of communication on the CAN serial data link should be diagnosed first.
- 8: The modules which can communicate indicate the module which cannot communicate. You must clear the DTC from these modules to avoid future misdiagnosis.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
| 1 | Install a scan tool. Start the engine. Retrieve DTCs from the engine control module (ECM). Is DTC U2104 set as current? | Go to DTC U2104 | Go to Step 2 |
| 2 | IMPORTANT: Use the control module ID number list in order to determine which module is not communicating on the controller area network (CAN) serial data bus. Turn the ignition ON, with the engine OFF. Test the following circuits of the module that is not communicating on the CAN serial data bus for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 7 | Go to Step 3 |
| 3 | Turn OFF the ignition. Test the ground circuits of the module that is not communicating on the CAN serial data bus for an open. Refer to the following procedures: Control Module References in Body Control System for the applicable Schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 7 | Go to Step 4 |
| 4 | Test the CAN serial data circuits of the module that is not communicating on the CAN serial data bus for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 5 |
| 5 | Inspect the harness connectors of the module that is not communicating on the CAN serial data bus for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The CAN serial data circuits Refer to the following procedures: Control Module References in Body Control System for the applicable schematic Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 7 | Go to Step 6 |
| 6 | IMPORTANT: Perform the programming or set up procedure for the module, if required. Replace the module that is not communicating on the CAN serial data bus. Refer to Control Module References for the applicable replacement procedure.Did you complete the replacement? | Go to Step 7 | |
| 7 | Select the Display DTCs function for the modules which had the Loss of Communications DTC set. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References in Body Control System | Go to Step 8 |
| 8 | Use the scan tool in order to clear the DTCs. Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared. Did you complete the action? | Go to Control Module References in Body Control System | |
| IMPORTANT |
|---|
| Use the control module ID number list in order to determine which module is not communicating on the controller area network (CAN) serial data bus. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the module, if required. |
DTC U1800, U2105, U2106, or U2108
The number below refers to the step number on the diagnostic table.
- 8: The module which was not communicating may have set Loss of Communication DTCs for those modules that it was monitoring.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List and Inline Harness Connector End Views in Wiring Systems | |||
| 1 | Was any DTC in the range U1001-U1254 recorded? | Go to DTC U1001-U1254 | Go to Step 2 |
| 2 | Was any DTC in the range U0100-U0299 recorded? | Go to DTC U0100-U0299 (Diesel Engine) DTC U0100-U0299 (HP2) | Go to Step 3 |
| 3 | IMPORTANT: Use the DTC Descriptors list in order to determine which module is not communicating. If multiple DTCs were set, consider the closest module to the powertrain control module (PCM) as the non-communicating module. A loss of voltage to the electric-hydraulic power steering (EHPS) hydraulic motor as well as to the module may cause a loss of communication. Test the following circuits of the module that is not communicating for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following: Control Module References in Body Control System for the applicable schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 4 |
| 4 | IMPORTANT: A loss of ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication. Turn OFF the ignition. Test the ground circuits of the module that is not communicating for an open. Refer to the following: Control Module References in Body Control System for the applicable Schematic Circuit Testing in Wiring Systems Wiring Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 5 |
| 5 | Test the class 2 or/and high speed GMLAN serial data circuits of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 8 | Go to Step 6 |
| 6 | Inspect the harness connectors of the module that is not communicating for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The class 2 or/and high speed GMLAN serial data circuits Refer to the following: Control Module References in Body Control System for the applicable schematic Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems Did you find and correct the condition? | Go to Step 8 | Go to Step 7 |
| 7 | IMPORTANT: Perform the programming or set up procedure for the module, if required. Replace the module that is not communicating. Refer to Control Module References for the applicable replacement procedure.Did you complete the replacement? | Go to Step 8 | |
| 8 | Install a scan tool. Turn ON the ignition with the engine OFF. Select the Display DTCs function for the module which was not communicating. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 9 |
| 9 | Select the Display DTCs function for the modules which had the Loss of Communications DTC set. Does the scan tool display any DTCs which do not begin with a "U"? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 10 |
| 10 | Use the scan tool in order to clear the DTCs. Continue diagnosing or clearing the DTCs until all the modules have been diagnosed and all the DTCs have been cleared. Did you complete the action? | Go to Control Module References for the applicable Diagnostic System Check | |
| IMPORTANT |
|---|
| Use the DTC Descriptors list in order to determine which module is not communicating. If multiple DTCs were set, consider the closest module to the powertrain control module (PCM) as the non-communicating module. A loss of voltage to the electric-hydraulic power steering (EHPS) hydraulic motor as well as to the module may cause a loss of communication. |
| IMPORTANT |
|---|
| A loss of ground to the EHPS hydraulic motor as well as to the module may cause a loss of communication. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the module, if required. |
DTC U1881-U1899
The number below refers to the step number on the diagnostic table.
- 4: If the battery positive voltage and ground circuits of the DLC are functioning properly. The malfunction must be due to the scan tool.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Data Link Communications Connector End Views | |||
| 1 | Test the battery positive voltage circuit of the data link connector (DLC) for an open or a short to ground. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | Go to Step 2 |
| 2 | Test the ground circuit from pin 4 of the DLC for an open or high resistance. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | Go to Step 3 |
| 3 | Inspect for poor connections and terminal tension at the DLC. Refer to Testing for Intermittent Conditions and Poor Connections or Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | Go to Step 4 |
| 4 | The scan tool may be malfunctioning. Refer to the scan tool user guide. Did you obtain a properly operating scan tool? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | |
Scan Tool Does Not Power Up
The numbers below refer to the step numbers on the diagnostic table.
- 2: A partial malfunction in the class 2 serial data circuit uses a different procedure from a total malfunction of the class 2 serial data circuit. The following modules communicate on the class 2 serial data circuit: The audio amplifier (AMP) - early production-Refer to «Radio/Audio System Description and Operation»(ref-184119-S42084544172005082200000) in Entertainment for more information. The body control module (BCM) The CD changer (CDX) The driver door module (DDM) The digital radio receiver (DRR) The driver seat module (DSM) The electronic brake control module (EBCM) The front passenger door module (FPDM) HVAC Control Module The hybrid control module (HCM), for PHT The instrument panel cluster (IPC) The powertrain control module (PCM) Radio The rear seat audio (RSA) controller The rear seat entertainment (RSE) assembly The rear wheel steering control module (RWSCM) The inflatable restraint sensing and diagnostic module (SDM) The transmission control module (TCM) The transfer case shift control module (TCSCM) The vehicle communication interface module (VCIM)
- 3: The following DTCs may be retrieved with a history status, but are not the cause of the present condition. U1300 U1301 U1305
- 6: A state of health DTC with a history status may be present along with a U1000 or U1255 code having a current status. This indicates that the malfunction occurred when the ignition was ON.
- 7: Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.
- 10: A poor connection at DLC terminal of the splice pack SP205 would cause this condition but will not set a DTC.
- 11: An open or a short in the class 2 serial data circuit between the DLC and splice pack SP205 will prevent the scan tool from communicating with any module. This condition will not set a DTC.
- 13: This test isolates the BCM class 2 serial data circuits.
- 16: The BCM detects that the ignition is ON and sends the appropriate power mode message to the other modules. Therefore, the BCM must remain connected to the DLC for any other module to communicate with the scan tool. This test isolates the splice pack SP207 serial data circuits.
- 21: This test isolates the rest of the splice pack SP205 serial data circuits.
- 25: If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.
- 26: The communication malfunction may have prevented diagnosis of the customer complaint.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
| 1 | Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up |
| 2 | Turn ON the ignition leaving the engine OFF. Attempt to communicate with each module on the class 2 serial data circuit. If using a Tech 2, obtain this information using the Class 2 Message Monitor feature. Does the scan tool communicate with any module on the class 2 serial data circuit? | Go to Step 3 | Go to Step 8 |
| 3 | Select the Display DTCs function for each module. If using a Tech 2, use the Class 2 DTC Check feature in order to determine which modules do have DTCs set. Record all of the displayed DTCs, the DTC status and the module which set the DTC. Did you record any DTCs in the range of U1000 to U1305? | Go to Step 4 | Go to Step 7 |
| 4 | Are the history DTCs U1300, U1301 or U1305 retrieved from any module? | Go to Step 5 | Go to Step 6 |
| 5 | IMPORTANT: Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions. Test the class 2 serial data circuit for an intermittent short to ground or an intermittent short to voltage. Refer to the following in Wiring Systems: Testing for Intermittent Conditions and Poor Connections Circuit Testing Connector Repairs Wiring Repairs Did you find and correct the condition? | Go to Step 25 | Go to Step 6 |
| 6 | Is U1000 the only DTC displayed in the previously specified range? | Go to DTC U1000 | Go to DTC U1001-U1254 |
| 7 | Diagnose the non-communicating module by using the DTC U1001-U1254 procedure for the module which is not communicating. Refer to DTC U1001-U1254 . Did you complete the action? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | |
| 8 | Turn OFF the ignition. Disconnect the scan tool from the data link connector (DLC). Inspect for poor connections at the DLC terminals 2 and 5. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | Go to Step 9 |
| 9 | Test the DLC ground circuit at terminal 5 for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | Go to Step 10 |
| 10 | Disconnect the splice pack SP205. Inspect for poor connections at the splice pack SP205. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References in Body Control System for the applicable Diagnostic System Check | Go to Step 11 |
| 11 | Test the class 2 serial data circuits between the splice pack SP205 and DLC for an open, a short to ground, or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 12 |
| 12 | Using the correct terminal adapter, connect a jumper wire to the DLC terminal of the splice pack SP205. Connect the other end of the jumper wire, using correct terminal adapter, to the body control module BCM terminal of the splice pack SP205. Turn ON the ignition leaving the engine OFF. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step 16 | Go to Step 13 |
| 13 | Turn OFF the ignition. Disconnect the powertrain control module (PCM). Turn ON the ignition leaving the engine OFF. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step 14 | Go to Step 15 |
| 14 | Turn OFF the ignition. Test the class 2 serial data circuit between the splice pack SP205 and the PCM for an open, a short to ground, or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 23 |
| 15 | Turn OFF the ignition. Disconnect the BCM. Test both class 2 serial data circuits of the BCM for an open, a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 23 |
| 16 | Leave the jumper wire connected to the DLC terminal and to the BCM terminal of the splice pack SP205. Connect another jumper wire from the jumper wire connected to the DLC terminal of the splice pack SP205. Connect the other end of the jumper wire, using correct terminal adapter, to the splice pack SP207 terminal of the splice pack SP205. Turn ON the ignition leaving the engine OFF. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step 21 | Go to Step 17 |
| 17 | Disconnect the splice pack SP207. Inspect for poor connections at the splice pack SP207. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step 19 | Go to Step 18 |
| 18 | Repair the class 2 serial data circuit for a short to ground or a short to voltage between the splice pack SP205 and the splice pack SP207. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | |
| 19 | Repeat the following steps on the class 2 serial data circuits connected to the splice pack SP207 until the concern is located: Connect another jumper wire to the splice pack SP205 terminal of the splice pack SP207. Connect the other end of the jumper wire, using correct terminal adapter, to the terminal for the devices connected to splice pack SP207. Turn ON the ignition leaving the engine OFF. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step 25 | Go to Step 20 |
| 20 | Turn OFF the ignition. Disconnect the module that caused the no communication condition. Test the class 2 serial data circuit between the splice pack SP207 and the respective module for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 23 |
| 21 | Repeat the following steps on the class 2 serial data circuits connected to the splice pack SP205 until the concern is located: Disconnect the jumper wire from the splice pack SP207 terminal of the splice pack SP205. Connect the jumper wire, using correct terminal adapter, to the terminal for the rest of devices connected to splice pack SP205, one by one. Turn ON the ignition leaving the engine OFF. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step 25 | Go to Step 22 |
| 22 | Turn OFF the ignition. Disconnect the module that caused the no communication condition. Test the class 2 serial data circuit between the splice pack SP205 and the respective module for a short to ground or a short to voltage. Turn ON the ignition leaving the engine OFF when testing for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 23 |
| 23 | Inspect for poor connections at the class 2 serial data circuit of the last disconnected module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 24 |
| 24 | IMPORTANT: Perform the module setup procedure if required. Replace the last disconnected module. Refer to Control Module References in Body Control System for the appropriate repair instructions.Did you complete the replacement? | Go to Step 25 | |
| 25 | Reconnect all of the disconnected modules. Reconnect any other disconnected connectors. Install a scan tool. Turn ON the ignition leaving the engine OFF. Wait for 10 seconds. The scan tool may require a power up reset before communication will occur due to a short on the class 2 serial data circuit. Turn OFF the scan tool prior to performing this test. Select the Display DTCs function for each module. If using a Tech 2, use the Class 2 DTC Check feature in order to determine which modules do have DTCs set. Record all of the displayed DTCs and the DTC status. Did you record any DTCs which begin with a "U" and with a current status? | Go to Step 27 | Go to Step 26 |
| 26 | Did you record any DTCs which do not begin with a "U"? | Go to Step 27 | Go to Step 29 |
| 27 | Diagnose the DTCs as directed by the diagnostic procedures for the particular module or malfunction. Refer to Control Module References in Body Control System for the applicable Diagnostic System Check. Did you complete the action? | Go to Step 28 | |
| 28 | Did you diagnose all of the DTCs? | Go to Step 29 | Go to Step 27 |
| 29 | Use the scan tool in order to clear the DTCs. Did you complete the action? | System OK | |
| IMPORTANT |
|---|
| Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use the DMM MIN/MAX function to capture intermittent conditions. |
| IMPORTANT |
|---|
| Perform the module setup procedure if required. |
Scan Tool Does Not Communicate with Class 2 Device