Endurant XD
TRTS0960 EN-US
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September 2024 - A

Fault Code 170: Front Axle Speed

J1939: SA 3 SPN 904 FMI 9, 13, 19

Overview

The Transmission Control Module (TCM) receives the vehicle’s Front Axle Speed message from a vehicle Electronic Control Unit (ECU) over the Primary Data Link (J1939A). This message is used by the TCM to maintain transmission operation in the event the transmission output shaft sensor fails.

Detection

The TCM monitors Front Axle Speed 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: Front Axle Speed message not received for 5 seconds.

FMI 13 – Out of Calibration: Front Axle Speed message not available for 5 seconds.

FMI 19 – Received Network Data in Error: Front Axle Speed messages invalid for 5 seconds.

Fallback

FMI 9, 13, 19:

  • Amber warning lamp on
  • No degraded modes

Note: Vehicle may have additional fallback modes. Refer to OEM.

Conditions to Set Fault Code Inactive

FMI 9, 13, 19: Front Axle Speed messages received and valid for 10 seconds.

Possible Causes

FMI 9, 13, 19:

  • Vehicle Components
    • Front Axle Speed Sensor message notenabled
    • Other vehicle ECU(s) faulted
  • Vehicle Harness - Primary Data Link (J1939A)
    • Wiring shorted to power, shorted to ground or open
    • Terminals bent, spread, corroded, or loose

Note: Refer to OEM for troubleshooting a failed system.

Fault Code 170 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 170 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V

  • If Fault Code 170 FMI 9, 19 is Active or Inactive, Go to Step B

  • If Fault Code 170 FMI 13 is Active, refer to OEM and enable vehicle Front Axle Speed message (SPN 904). Go to Step V

  • If Fault Code 170 FMI 13 is Inactive, Go to Step V

B
Purpose:Monitor Front Axle Speed signal message.

  1. Key on with engine off.

  2. Connect ServiceRanger.

  3. Go To “Data Monitor”.

  4. Select “Speed”.

  5. Select “Front axle speed”.

  6. Select all “- 904” SPN sources.

    Note: Not all sources will indicate a value.

  7. Monitor 904 - Front axle speed value. Record reading in table.

  8. Compare reading(s) in table.

  • If readings are out of range, refer to OEM guidelines for repair of the vehicle Front Axle Speed message (SPN 904). Go to Step V

  • If readings are in range and no fault was found, the intermittent nature of the fault makes it likely that the problem is in the vehicle Front Axle Speed message (SPN 904). Contact OEM for further diagnostic instructions. Go to Step V

ParameterRangeReading(s)
904 - Front Axle Speed0 RPM
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.