Fault Code 984: Auxiliary Trans Selected Gear

J1939: SA 3 SPN 15202 FMI 9, 13, 19

Overview

The Endurant XD Series transmission can be combined with a 2-speed auxiliary transmission for additional gear ratio coverage. When auxiliary transmission operation is required the Transmission Control Module (TCM) receives a gear engagement signal (Input) then adjusts the transmission shift strategy and launch characteristics for the new auxiliary transmission gear ratio. Reference Endurant XD Driver Instructions TRDR0960 for Auxiliary Transmission operation.

The TCM can be configured for operation with a 2-speed auxiliary transmission with messages over the vehicle Primary Data Link J1939A or from a switch circuit hardwired directly to the TCM. The TCM is equipped to receive 4 switch inputs and control 3 relay outputs that can be configured in an Input/Output (I/O) Package to support various vocational features.

If the TCM is configured to "2-Speed Aux Trans - (Low, (N), Direct) - J1939", auxiliary transmission gear engagement messages are provided to the TCM by an OEM vehicle ECU. If the TCM is configured to "2-Speed Aux Trans - (Low, (N), Direct) - TCM Hardwired", auxiliary transmission gear engagement notification signal (Input) is provided to the TCM from a hardwired switch circuit.

The auxiliary transmission circuit input is connected to the TCM in the 20-Way TCM Body Harness Connector. The auxiliary transmission circuit is installed by the OEM or body builder. Reference Input / Output Calibration in the Appendix for recommended Auxiliary Transmission circuit wiring diagrams.

Detection

The TCM monitors Auxiliary Transmission Selected Gear messages. If messages are not received or are invalid, the fault is set Active.

Conditions to Set Fault Code Active

FMI 9 – Abnormal Update Rate: Auxiliary Transmission Selected Gear messages not received for 5 seconds.

FMI 13 – Out of Calibration: Auxiliary Transmission Selected Gear message not available for 5 seconds.

FMI 19 – Received Network Data in Error: Auxiliary Transmission Selected Gear messages invalid for 5 seconds.

Fallback

FMI 9, 13, 19:

  • Amber warning lamp on
  • No degraded modes
  • Auxiliary Trans Selected Gear inoperative

Conditions to Set Fault Code Inactive

FMI 9, 13, 19: Auxiliary Transmission Selected Gear messages received and valid for 1 second.

Possible Causes

FMI 9, 13, 19:

  • Vehicle Components - Vehicle ECU(s)
    • Auxiliary Transmission Selected Gear message not enabled
    • Other vehicle ECU(s) faulted
  • Vehicle Harness - Primary Data Link (J1939A)
    • Shorted to power, shorted to ground or open circuit
    • Terminals bent, spread, corroded, or loose

Additional Tools

  • None

Fault Code 984 Troubleshooting

A
Purpose:Check for Active or Inactive fault codes.
  1. Set vehicle parking brake and chock wheels.

  2. Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.

  • If Fault Code 984 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V

  • If Fault Code 984 FMI 9 or 19 is Active or Inactive, refer to OEM guidelines for repair of the vehicle Auxiliary Transmission Selected Gear message (SPN 15202). Go to Step V

  • If Fault Code 984 FMI 13 is Active, refer to OEM and enable Auxiliary Transmission Selected Gear message (SPN 15202). Go to Step V

  • If Fault Code 984 FMI 13 is Inactive, Auxiliary Transmission Selected Gear is properly configured. Go to Step V

V
Purpose:Verify repair.
  1. Key off.

  2. Reconnect all connectors and verify all components are properly installed.

  3. Key on with engine off.

  4. Connect ServiceRanger.

  5. Go To “Fault Codes”.

  6. Select “Clear All Faults”.

  7. Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.

  8. Check for fault codes using ServiceRanger.