Fault Code 116: Secondary Data Link (J1939B)
J1939: SA 3 SPN 1231 FMI 9, 14
Overview
The Transmission Control Module (TCM) communicates with other vehicle Electronic Control Units (ECUs) over the vehicle J1939 data link. The TCM uses two vehicle J1939 data links to send and receive messages: the Primary Data Link (J1939A) and the Secondary Data Link (J1939B). The Primary Data Link is used by the TCM to send and receive messages to and from the Engine ECU, Anti-Lock Brake ECU and other vehicle ECUs to complete transmission shift operations. The Secondary Data Link is used in the event that the Primary Data Link is inoperative. The Primary Data Link (J1939A) is connected to the TCM at the 20-Way TCM Vehicle Harness Connector. The Secondary Data Link (J1939B) is connected to the TCM at the 20-Way TCM Body Harness Connector.
The TCM monitors vehicle and Engine ECU broadcast messages. If messages are not received or are invalid, the fault is set Active. Detection
Conditions to Set Fault Code Active
FMI 9 – Abnormal Update Rate: Secondary Data Link (J1939B) vehicle ECU(s) messages not received for 5 seconds. FMI 14 – Special Instructions: Secondary Data Link (J1939B) Engine ECU messages not received for 5 seconds while the TCM is receiving messages from other vehicle ECU(s).
FMI 9, 14:Fallback
Conditions to Set Fault Code Inactive
FMI 9: Secondary Data Link (J1939B) vehicle ECU(s) messages received and valid for 10 seconds. FMI 14: Valid vehicle Secondary Data Link (J1939B) Engine ECU messages received for 10 seconds.
Possible Causes
FMI 9: FMI 14: Note: Refer to OEM for troubleshooting a failed system.
Additional Tools
1. 20-Way TCM Vehicle Harness Connector 2. 20-Way TCM Body Harness Connector 3. Transmission Control Module (TCM) 4. 9-Way Type 2 Diagnostic Connector (In Cab) 1. Transmission Control Module (TCM) 2. 20-Way TCM Vehicle Harness Connector 3. 20-Way TCM Body Harness Connector 4A. 9-Way Type 2 Diagnostic Connector (OEM-Specific Primary Data Link FG) 4B. 9-Way Type 2 Diagnostic Connector (OEM-Specific Primary Data Link CD)Component Identification
Fault Code 116 Troubleshooting
A Purpose:Check for active or inactive fault codes. Set vehicle parking brake and chock wheels. Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure. If Fault Code 116 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes first. Go to Step V If Fault Code 116 FMI 9 is Active or Inactive, Go to Step B If Fault Code 116 FMI 14 is Active, Go to Step N If Fault Code 116 FMI 14 is Inactive, the intermittent nature of the fault makes it likely one of the following conditions exists: Refer to OEM guidelines for repair or replacement of the vehicle Secondary Data Link (J1939 B), vehicle harness, or Engine ECU. Go to Step V B Purpose:Verify Secondary Data Link (J1939B) Baud Rate configured in TCM and installed on vehicle. Key off. Allow TCM to perform a complete power down. Key on with engine off. Connect ServiceRanger. Go to “Configuration”. Select “Vehicle”. Record “Secondary J1939 Baud Rate” Current Value in table. Record secondary J1939 baud rate installed on vehicle in table. Note: Vehicle's secondary J1939 baud rate (250K or 500K) is determined by OEM. Refer to OEM regarding secondary J1939 baud rate installed on the vehicle. Compare reading(s) in table. If “Secondary J1939 Baud Rate” is not configured correctly, select correct configuration from “New Value” drop down list, select “Apply” and follow on screen prompts. Go to Step V If FMI 9 is Active and “Secondary J1939 Baud Rate” is configured correctly, Go to Step C C Purpose:Identify TCM location on vehicle Secondary Data Link (J1939B). Key off. Refer to OEM to identify TCM J1939 pin locations on vehicle 9-Way J1939 Diagnostic Connector. If the TCM is on Pins C and D, Go to Step D If the TCM is on Pins H and J, Go to Step I D Purpose:Verify vehicle Secondary Data Link (J1939 B) signal voltage. Key on with engine off. Measure voltage between 9-Way Diagnostic Connector Pin C and Pin A. Record reading in table. Measure voltage between 9-Way Diagnostic Connector Pin D and Pin A. Record reading in table. Record Total Voltage in table by adding voltage readings together. Compare reading(s) in table. If readings are in range, Go to Step E If readings are out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V E Purpose:Verify resistance of vehicle Secondary Data Link (J1939B). Key off. Measure resistance between 9-Way Diagnostic Connector Pin C and Pin D. Record reading in table. Compare reading(s) in table. If readings are out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V If readings are in range, Go to Step F F Purpose:Verify 20-Way TCM Body Harness Connector condition. Key off. Disconnect 20-Way TCM Body Harness Connector from TCM. Inspect 20-Way TCM Body Harness Connector, verify connector is free from contamination and corrosion; terminals are not bent, spread or loose; and there is no damage to connector body. Inspect 20-Way TCM Body Connector, verify connector is free from contamination and corrosion; terminals are not bent, spread or loose; and there is no damage to connector body. If contamination or damage is found, refer to OEM guidelines for repair or replacement of 20-Way TCM Body Harness Connector. Go to Step V If no contamination or damage is found, Go to Step G G Purpose:Verify resistance of vehicle Secondary Data Link (J1939B) at 20-Way TCM Body Harness Connector. Key off. Measure resistance between 20-Way TCM Body Harness Connector Pin 7 and Pin 8. Record reading in table. Compare reading(s) in table. If readings are out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V If readings are in range, Go to Step H H Purpose:Verify fault code status. Key off. Reconnect all connectors and verify all components are properly installed. Key on with engine off. Connect ServiceRanger. Go To “Fault Codes”. Retrieve and record transmission fault codes, FMIs, occurrences, and timestamps. If Fault Code 116 is Inactive, an intermittent wiring problem exists in the vehicle Secondary Data Link (J1939B). Refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B) harness and/or 20-Way TCM Vehicle Harness Connector. Go to Step V If Fault Code 116 is Active and no fault was found with the vehicle Secondary Data Link (J1939B), replace Transmission Control Module (TCM). Go to Step V Note: If troubleshooting indicates no fault found in wiring or connections to TCM, ensure an intermittent issue does not exist in wiring or connections before replacing TCM. I Purpose:Verify vehicle Secondary Data Link (J1939B) signal voltage. Key on with engine off. Measure voltage between 9-Way Diagnostic Connector Pin H and Pin A. Record reading in table. Measure voltage between 9-Way Diagnostic Connector Pin J and Pin A. Record reading in table. Record Total Voltage in table by adding voltage readings together. Compare reading(s) in table. If readings are in range, Go to Step J If readings are out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V J Purpose:Verify resistance of vehicle Secondary Data Link (J1939B). Key off. Measure resistance between 9-Way Diagnostic Connector Pin H and Pin J. Record reading in table. Compare reading(s) in table. If reading is out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V If reading is in range, Go to Step K K Purpose:Verify 20-Way TCM Body Harness Connector condition. Key off. Disconnect 20-Way TCM Body Harness Connector from TCM. Inspect 20-Way TCM Body Harness Connector, verify connector is free from contamination and corrosion; terminals are not bent, spread or loose; and there is no damage to connector body. Inspect 20-Way TCM Body Connector, verify connector is free from contamination and corrosion; terminals are not bent, spread or loose; and there is no damage to connector body. If contamination or damage is found, refer to OEM guidelines for repair or replacement of 20-Way TCM Body Harness Connector. Go to Step V If no contamination or damage is found, Go to Step L L Purpose:Verify resistance of vehicle Secondary Data Link (J1939B) at 20-Way TCM Body Harness Connector. Key off. Measure resistance between 20-Way TCM Body Harness Connector Pin 7 and Pin 8. Record reading in table. Compare reading(s) in table. If readings are out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V If readings are in range, Go to Step M M Purpose:Verify fault code status. Key off. Reconnect all connectors and verify all components are properly installed. Key on with engine off. Connect ServiceRanger. Go To “Fault Codes”. Retrieve and record transmission fault codes, FMIs, occurrences, and timestamps. If Fault Code 116 is Inactive, an intermittent wiring problem exists in the vehicle Secondary Data Link (J1939B). Refer to OEM guidelines for repair or replacement of the vehicle Secondary Data Link (J1939B) harness and/or 20-Way TCM Vehicle Harness Connector. Go to Step V If Fault Code 116 is Active and no fault was found with the vehicle Secondary Data Link (J1939B), replace Transmission Control Module (TCM). Go to Step V Note: If troubleshooting indicates no fault found in wiring or connections to TCM, ensure an intermittent issue does not exist in wiring or connections before replacing TCM. N Purpose:Verify resistance of vehicle Secondary Data Link (J1939B) at Engine ECU vehicle harness connector. Key off. Locate and disconnect Engine ECU vehicle harness connector containing the vehicle Secondary Data Link (J1939B). Note: Refer to OEM guidelines for Engine ECU vehicle harness connector location, connector removal, and J1939 High (+) and J1939 Low (-) connector pin locations. Measure resistance between Engine ECU vehicle harness connector Pin J1939 High (+) and Pin J1939 Low (-). Record reading in table. Compare reading(s) in table. If readings are out of range, refer to OEM guidelines for repair or replacement of vehicle Secondary Data Link (J1939B). Go to Step V If readings are in range, Engine ECU has continuity to the vehicle Secondary Data Link (J1939B). The intermittent nature of the fault makes it likely one of the following conditions exists: an Engine ECU message fault exists and/or the Engine ECU may intermittently not be powering up. Contact OEM for further diagnostic instructions. Go to Step V V Purpose:Verify repair. Key off. Reconnect all connectors and verify all components are properly installed. Key on with engine off. Connect ServiceRanger. Go To “Fault Codes”. Select “Clear All Faults”. Operate vehicle and attempt to reset the fault code or duplicate the previous complaint. Check for fault codes using ServiceRanger. If no fault codes set and vehicle operates properly, test complete. If Fault Code 116 sets Active, Go to Step A If a fault code other than 116 sets Active, troubleshoot per the Fault Code Isolation Procedure IndexLocation Secondary J1939 Baud Rate TCM (ServiceRanger) Vehicle 
Pins Range Reading(s) C to A N/A D to A N/A + Total Voltage 4.5–5.5 V = 
Pins Range Reading(s) C to D 50–70 Ohms 
Pins Range Reading(s) 7 to 8 50–70 Ohms 
Pins Range Reading(s) H to A N/A J to A N/A + Total Voltage 4.7–5.3 V = 
Pins Range Reading(s) H to J 50–70 Ohms Pins Range Reading(s) 7 to 8 50–70 Ohms 
Pins Range Reading(s) J1939 High (+) to J1939 Low (-) 50–70 Ohms
