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. IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown: The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires. The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)
Scheme 1
Scheme 2
Scheme 3
Scheme 4
| Callout | Component Name |
|---|---|
| 1 | Engine Control Module (ECM) - L61 |
| 2 | Engine Control Module (ECM) - L81 |
| 3 | Power Steering Control Module (PSCM) |
| 4 | Body Control Module (BCM), Radio |
| 5 | Door Lock Switch and Actuator - Front Passenger, Rest Similar |
| 6 | Inflatable Restraint Sensing and Diagnostic Module (SDM) |
| 7 | Liftgate Lock Actuator/Ajar Switch |
| 8 | Data Link Connector (DLC) |
| 9 | Vehicle Communication Interface Module (VCIM) |
| 10 | Instrument Panel Cluster (IPC) |
| 11 | Passlock Sensor |
| 12 | Transmission Control Module (TCM) |
| 13 | Electronic Brake Control Module (EBCM) |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 3: This test isolates a shorted TCM, ECM, or EBTCM. By reading the signal from the ECM after the wiring is tested, without a TCM connected, an ECM signal generating problem can be diagnosed. When the CAN circuits are open between two components, both components generate a 30,000 to 40,000 hertz signal. When the system is not open, the frequency is 3,000 to 3,500 hertz.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics (A/T) or Data Link Connector (DLC) Schematics (M/T) Connector End View Reference: Data Link Communications Connector End Views | ||||
| 1 | Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition? | Go to Step 2 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
| 2 | IMPORTANT: Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use DMM MIN/MAX function to compare intermittent conditions. Turn OFF the ignition. Disconnect the ECM, TCM if applicable, and EBTCM harness connectors which contain CAN circuits. Test the CAN serial data circuits for a short to ground, short to voltage, or a short between the CAN High and CAN Low circuits. 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 11 | Go to Step 3 | |
| 3 | IMPORTANT: If the vehicle is not equipped with a TCM, answer YES to this step. Turn OFF the ignition. Reconnect the TCM, if equipped. Clear any DTCs in memory. Start the engine. Measure the frequency across the CAN circuits in the harness with a DMM. Does the frequency measure more than the specified value? | 35,000 Hz | Go to Step 4 | Go to Step 6 |
| 4 | Turn OFF the ignition. Reconnect the EBTCM, if equipped. Clear any DTCs in memory. Start the engine. Measure the frequency across the CAN circuits in the harness with a DMM. Does the frequency measure more than the specified value? | 35,000 Hz | Go to Step 5 | Go to Step 7 |
| 5 | Inspect for an intermittent or poor connection at the ECM. 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 11 | Go to Step 8 | |
| 6 | Inspect for an intermittent or poor connection at the TCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you fine and correct the condition? | Go to Step 11 | Go to Step 9 | |
| 7 | Inspect for an intermittent or poor connection at the EBTCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you fine and correct the condition? | Go to Step 11 | Go to Step 10 | |
| 8 | IMPORTANT: Perform the module setup procedure, if required. Replace the ECM (L61). Refer to Engine Control Module (ECM) Replacement in Engine Controls - 2.2L (L61).Did you complete the replacement? | Go to Step 11 | ||
| 9 | IMPORTANT: Perform the module setup procedure, if required. Replace the TCM (5AT). Refer to Powertrain Control Module (PCM) Replacement in Automatic Transmission - (5AT).Did you complete the replacement? | Go to Step 11 | ||
| 10 | IMPORTANT: Perform the module setup procedure, if required. Replace the EBCM. Refer to Electronic Brake Control Module Replacement in Antilock Brakes.Did you complete the replacement? | Go to Step 11 | ||
| 11 | Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 12 | |
| 12 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List | System OK | |
| IMPORTANT |
|---|
| Turn ON the ignition, with the engine OFF, when testing for a short to voltage. Use DMM MIN/MAX function to compare intermittent conditions. |
| IMPORTANT |
|---|
| If the vehicle is not equipped with a TCM, answer YES to this step. |
| IMPORTANT |
|---|
| Perform the module setup procedure, if required. |
| IMPORTANT |
|---|
| Perform the module setup procedure, if required. |
| IMPORTANT |
|---|
| Perform the module setup procedure, if required. |
DTC U0073
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 (A/T) or Data Link Connector (DLC) Schematics (M/T) Connector End View Reference: Data Link Communications Connector End Views | |||
| 1 | Install a scan tool. Start the engine. Retrieve DTCs from engine control module (ECM). Is DTC U0073 set as current? | Go to DTC U0073 | Go to Step 2 |
| 2 | IMPORTANT: Use the control module ID number list in order to determine which module is not communicating on CAN serial data bus. Turn ON the ignition, with the engine OFF. Test the following circuits of the module that is not communicating on 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: Control Module References 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 CAN serial data bus for an open. Refer to the following: Control Module References 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 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 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: Control Module References 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 setup procedure for the module, if required. Replace the module that is not communicating on 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 CAN serial data bus. |
| IMPORTANT |
|---|
| Perform the programming or setup procedure for the module, if required. |
DTC U0100-U0299
The numbers below refer to the step numbers on the diagnostic table.
- 2: A DTC U1001-U1254 Lost Communications with XXX with a history status may indicate the cause of U1000.
- 3: 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.
- 8: 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.
- 10: The modules which can communicate indicate the module which can not communicate. You must clear the serial data communication DTCs from these modules to avoid future misdiagnosis.
- 13: If all modules are communicating, the module which set U1000 may have done so due to some other condition.
- 15: The module which set U1000 is the likely cause of the malfunction.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics (A/T) or Data Link Connector (DLC) Schematics (M/T) Connector End View Reference: Master Electrical Component List in Wiring Systems. | |||
| 1 | Did you perform the Diagnostic System Check for the system exhibiting symptom? | Go to Step 2 | Go to Control Module References in Body Control System for the applicable Diagnostic System Check |
| 2 | 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 3 |
| 3 | 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 4 | Go to Step 13 |
| 4 | 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 9 | Go to Step 5 |
| 5 | 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 9 | Go to Step 6 |
| 6 | IMPORTANT: Inspect all connectors in the serial data communications circuit. Refer to the following: Data Link Connector (DLC) Schematics (A/T) or Data Link Connector (DLC) Schematics (M/T) 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 (A/T) or Data Link Connector (DLC) Schematics (M/T) Circuit Testing in Wiring Systems. Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 7 | 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 9 | Go to Step 8 |
| 8 | IMPORTANT: Perform the programming or set up procedure for the replaced control 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 11 | |
| 9 | 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 the applicable Diagnostic System Check | Go to Step 10 |
| 10 | Use the scan tool in order to clear the DTCs. Did you complete the action? | Go to Step 11 | |
| 11 | 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 the applicable Diagnostic System Check | Go to Step 12 |
| 12 | Use the scan tool in order to clear the DTCs. Did you complete the action? | System OK | |
| 13 | 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 the applicable Diagnostic System Check | Go to Step 14 |
| 14 | 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 15 | Go to Diagnostic Aids |
| 15 | IMPORTANT: Perform the programming or set up procedure for the replaced control module if required. Replace the module which had U1000 set as a current DTC. Refer to Control Module References in Body Control System for the applicable replacement procedure.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 (A/T) or Data Link Connector (DLC) Schematics (M/T) Testing for Intermittent Conditions and Poor Connections in Wiring Systems Connector Repairs in Wiring Systems |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the replaced control module if required. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the replaced control module if required. |
DTC U1000 Diagnostic Test
The number below refers to the step number on the diagnostic table.
- 7: The module which was not communicating on the class 2 serial data circuit may have set the Loss of Communication DTCs for the modules it was monitoring.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics (A/T) or Data Link Connector (DLC) Schematics (M/T) Connector End View Reference: Master Electrical Component List in Wiring Systems. | |||
| 1 | Did you perform the Diagnostic System Check for the system exhibiting symptom? | Go to Step 2 | Go to Control Module References in Body Control System for the applicable Diagnostic System Check |
| 2 | 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 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 for an open. Refer to the following: Control Module References in Body Control System 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 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 7 | Go to Step 5 |
| 5 | 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 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 replaced control 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 7 | |
| 7 | 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 | Go to Step 8 |
| 8 | 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 9 |
| 9 | 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. |
| IMPORTANT |
|---|
| Perform the programming or set up procedure for the replaced control module if required. |
DTC U1001-U1254 Diagnostic Test
The number below refers to the step number on the diagnostic table.
- 4: If the battery positive voltage and ground circuits of the data link connector (DLC) are functioning properly, the malfunction must be due to the scan tool.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics (A/T) or Data Link Connector (DLC) Schematics (M/T) Connector End View Reference: Data Link Communications Connector End Views | |||
| 1 | Test the battery positive voltage circuit of the DLC for an open or a short to ground. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to 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.
- 3: A partial loss of communication in the class 2 serial data circuit uses a different procedure than a total loss of communication of the class 2 serial data circuit.
- 5: The following DTCs may be retrieved with a history status. These DTCs are not the cause of the present condition. U1300 U1301
- 7: A State of Health DTC with a history status may be present along with a U1000 with a current status. This indicates that the malfunction occurred when the ignition was ON.
- 11: This step will isolate a wiring problem or a module malfunction.
- 13: This step analyzes the specific branch circuit for a malfunction.
- 14: An open circuit at this point will cause a loss of communication with the vehicle.
- 19: If there are no current DTCs that begin with the letter "U", the communication concern has been repaired.
- 21: The communication concern may have prevented diagnosis of the customer complaint.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Data Link Connector (DLC) Schematics (A/T) or Data Link Connector (DLC) Schematics (M/T) Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
| 1 | Did you perform the Diagnostic System Check for the system exhibiting symptom? | Go to Step 2 | Go to Control Module References in Body Control System for the applicable Diagnostic System Check |
| 2 | Install a scan tool. Does the scan tool power up? | Go to Step 3 | Go to Scan Tool Does Not Power Up |
| 3 | 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. Does the scan tool communicate with any module on the class 2 serial data circuit? | Go to Step 4 | Go to Step 9 |
| 4 | 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 U1255? | Go to Step 5 | Go to Step 8 |
| 5 | Are history DTCs U1300 or U1301 retrieved from any module? | Go to Step 6 | Go to Step 7 |
| 6 | 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 18 | Go to Step 7 |
| 7 | Is U1000 the only DTC displayed in the previously specified range? | Go to DTC U1000 | Go to DTC U1001-U1254 |
| 8 | Diagnose the non communicating module by using the DTC U1001-U1254 Lost Communications with XXX procedure for the module which is not communicating. The DTC U1001-U1254 Lost Communications with XXX procedure will determine which module is not communicating. Refer to DTC U1001-U1254 . Did you complete the action? | Go to Control Module References in Body Control Systems for the applicable Diagnostic System Check | |
| 9 | Turn OFF the ignition. Disconnect the scan tool from the data link connector (DLC). Inspect for poor connections and terminal tension at the DLC. 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 Systems for the applicable Diagnostic System Check | Go to Step 10 |
| 10 | Test the ground circuits of the DLC for an open or high resistance. 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 Systems for the applicable Diagnostic System Check | Go to Step 11 |
| 11 | Disconnect all modules on the class 2 serial data circuit. IMPORTANT: Turn ON the ignition, leaving the engine OFF, when testing for a short to voltage. Test the class 2 serial data circuit for a short to ground or short to voltage between DLC terminal 2 and each module on the class 2 serial data circuit. Did you find and correct the condition? | Go to Step 18 | Go to Step 12 |
| 12 | Turn OFF the ignition. Reconnect the BCM. Install the scan tool. Turn ON the ignition, with the engine OFF. Attempt to communicate with the BCM. Does the scan tool communicate with the BCM? | Go to Step Step 13 | Go to Step Step 14 |
| 13 | Continue connecting the disconnected modules and attempting to communicate after each connection until communication can not be established or all modules are reconnected. When a module is connected, is communication lost with the class 2 serial data devices? | Go to Step 15 | Go to Diagnostic Aids |
| 14 | Inspect for poor connections and terminal tension at the class 2 serial data circuit of the BCM. Did you find and correct the condition? | Go to Step 18 | Go to Step 16 |
| 15 | Inspect for poor connections and terminal tension at the class 2 serial data circuit of the most recently reconnected module. Did you find and correct the condition? | Go to Step 18 | Go to Step 17 |
| 16 | IMPORTANT: Perform the programming or setup procedure for the replaced control module if required. Replace the BCM. Refer to Body Control Module Replacement in Body Control System for the applicable replacement procedure.Did you complete the replacement? | Go to Step 18 | |
| 17 | IMPORTANT: Perform the programming or setup procedure for the replaced control module if required. Replace the most recently reconnected module. Refer to Control Module References in Body Control System for the appropriate replacement procedure.Did you complete the replacement? | Go to Step 18 | |
| 18 | Connect all of the modules. Connect all the connectors. Install a scan tool. Turn ON the ignition, leaving the engine OFF. IMPORTANT: 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 or disconnect the scan tool before you display DTCs. Wait for 10 seconds. 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 your record any DTCs which begin with a letter U and with a current status? | Go to Step 20 | Go to Step 19 |
| 19 | Did you record any DTCs which do not begin with a letter "U"? | Go to Step 20 | Go to Step 22 |
| 20 | Diagnose the DTCs as directed by the diagnostic procedures for the particular module or concern. Did you complete the action? | Go to Step 21 | |
| 21 | Did you diagnose all of the DTCs? | Go to Step 22 | Go to Step 20 |
| 22 | Clear the DTCs using the scan tool. Did you complete the action? | Go to Control Module References in Body Control Systems 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 |
|---|
| Turn ON the ignition, leaving the engine OFF, when testing for a short to voltage. |
| IMPORTANT |
|---|
| Perform the programming or setup procedure for the replaced control module if required. |
| IMPORTANT |
|---|
| Perform the programming or setup procedure for the replaced control module if required. |
| IMPORTANT |
|---|
| 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 or disconnect the scan tool before you display DTCs. |
Scan Tool Does Not Communicate with Class 2 Device