Fault Code 915: PTO 2 Engage

J1939: SA 3 SPN 3457 FMI 3, 4, 5, 6, 7, 12, 14, 31

Overview

The Endurant HD Transmission incorporates enhanced controls for Power Take-Off (PTO) operation. When PTO operation is required the Transmission Control Module (TCM) receives a request (Input) for PTO operation, determines if operating conditions are suitable, and supplies a signal (Output) to engage the PTO. Once engaged the TCM receives a confirmation to complete the operation. Reference Endurant HD Driver Instructions based on transmission model (TRDR0950/TRDR0955) for PTO operation.

The TCM can be configured to operate a PTO with messages over the vehicle Primary Data Link J1939A or from a PTO 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 "J1939 Control Only", PTO operation messages are exchanged between the TCM and a OEM vehicle ECU. If the TCM is configured to "Hardwire Control Only, PTO operation is controlled by Input and Output signals from a hardwired switch circuit. The TCM has the functionality to support operation of two PTOs at the same time; one over the Primary Data Link J1939A and one from a hardwired PTO switch circuit.

PTO circuit inputs and outputs are connected to the TCM in the 20-Way TCM Body Harness Connector. The PTO and PTO circuit are installed by the OEM or body builder. Reference Input / Output Calibration of the Appendix for recommended PTO circuit wiring diagrams.

Detection

The TCM monitors the PTO 2 Engage J1939 messages or the hardwired PTO 2 Engage circuit output signal. If the messages or signal are not received or are invalid, the fault is set Active.

Conditions to Set Fault Code Active

FMI 3 – Voltage Above Normal or Shorted High: PTO 2 Engage circuit output signal shorted to power for 5 seconds.

FMI 4 – Voltage Below Normal or Shorted Low: PTO 2 Engage circuit output signal shorted to ground for 5 seconds.

FMI 5 – Current Below Normal or Open Circuit: PTO 2 Engage circuit open for 5 seconds.

FMI 6 – Current Above normal or Grounded Circuit: PTO 2 Engage circuit output current out of range for 5 seconds.

FMI 7 – Mechanical System Not Responding: PTO 2 Engage commanded, but PTO 2 Confirm message or signal not received.

FMI 12 – Bad Intelligent Device: TCM has detected an internal processing error.

FMI 14 – Special Instructions: The TCM detected invalid I/O Package calibration.

FMI 31 – Condition Exists: The TCM detected invalid I/O Package calibration.

Fallback

All FMIs:

  • Amber warning lamp on
  • PTO 2 Mode prohibited

Conditions to Set Fault Code Inactive

FMI 3: PTO 2 Engage circuit not shorted to power for 10 seconds.

FMI 4: PTO 2 Engage circuit not shorted to ground for 10 seconds.

FMI 5: PTO 2 Engage circuit not open for 10 seconds.

FMI 6: PTO 2 Engage circuit output current in range for 10 seconds.

FMI 7: PTO 2 Confirm circuit corrected.

FMI 12: Key cycle and fault condition no longer exits.

FMI 14, 31: Valid I/O Package calibration file is configured in TCM.

Possible Causes

FMI 3, 4, 5, 6:

  • Vehicle Harness - PTO 2 Engage Circuit
    • Shorted to power, shorted to ground, or open circuit

FMI 7:

  • Vehicle Harness - PTO 2 Confirm Circuit
    • Open circuit
  • Vehicle Components - PTO 2 Confirm and Engage Circuits
    • Switch stuck open
    • Relay latch failure
  • Vehicle Components - PTO Mechanical
    • Failure to engage

FMI 12:

  • TCM
    • Internal failure
    • Software issue

FMI 14, 31:

  • TCM
    • Invalid I/O Package calibration file configured in TCM

Fault Code 915 Troubleshooting

A
Purpose:Identify Transmission Model.
  1. Set vehicle parking brake and chock wheels.

  2. Record transmission model from Service Activity Report created during the Diagnostic Procedure.

B
Purpose:Check for Active or Inactive fault codes.
  1. Record the transmission fault codes, FMIs, occurrences, and timestamps from the Service Activity Report created during the Diagnostic Procedure.

C
Purpose:Verify Hardwire controlled PTO 2 configuration with ServiceRanger.
  1. Key on.

  2. Connect ServiceRanger.

  3. Go To “Configurations”.

  4. Select “PTO”.

  5. Record “PTO 2” Current Value.

  • If “PTO 2” Current Value indicates “Disabled” and a PTO is properly installed and wired, select a “Hardwire Control Only” option and follow on-screen prompts. Go to Step V

  • If “PTO 2” Current Value indicates a “Hardwire Control Only” option and a PTO is properly installed and wired, refer to OEM or body builder guidelines for repair or replacement of “PTO 2” Engage circuits. Go to Step V

    Note: PTO and wiring are installed by the OEM or body builder, reference TRIG2610 for PTO system installation and wiring diagrams.

D
Purpose:Verify PTO 2 operation and Confirm feedback.
  1. Key on with engine running.

  2. Select transmission PTO 2 request switch to off (if necessary).

  3. Connect ServiceRanger.

  4. Go To “Data Monitor”

  5. From the “Default Parameter Files” tab, select “Transmission PTO”.

  6. Monitor 520536 – PTO Confirmation Voltage value. Record reading in table.

  7. Select transmission PTO 2 request switch to on.

  8. Monitor 520536 – PTO Confirmation Voltage value. Record reading in table.

  9. Compare reading(s) in table.

    Note: PTO and wiring are installed by the OEM or body builder, reference TRIG2610 for PTO system installation and wiring diagrams.

  • If readings are in range, no fault was found. The intermittent nature of the fault makes it likely that the problem is in the PTO, PTO 2 confirmation switch and/or wiring. Refer to OEM or body builder guidelines for repair or replacement. Go to Step V

  • If readings are out of range, refer to OEM or body builder guidelines for repair or replacement of the PTO, PTO 2 confirmation switch and/or wiring.Go to Step V

ParameterRangeReading(s)
PTO 2 Off
520536 – PTO Confirmation Voltage4.5–5.5 V
PTO 2 On
520536 – PTO Confirmation Voltage0.0–0.5 V
E
Purpose:Check for Active or Inactive fault codes.
  1. Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.

  • If Fault Code 915 FMI 3, 4, 5, or 6 is Active, Go to Step F

  • If Fault Code 915 FMI 3, 4, 5, or 6 is Inactive, the intermittent nature of the fault makes it likely that the problem is in the PTO 2 Engage circuit. Go to Step H

    Note: PTO and circuit wiring are installed by OEM or body builder.

  • If Fault Code 915 FMI 7 is Active or Inactive, Go to Step G

  • If Fault Code 915 FMI 12 is Active, replace Transmission Control Module (TCM). Go to Step V

  • If Fault Code 915 FMI 12 is Inactive, Go to Step V

  • If Fault Code 915 FMI 14 or 31 is Active, Contact Eaton Cummins Automated Transmission Technologies for further diagnostic instructions. For Help Line phone numbers, go to Contact Information. Go to Step V

  • If Fault Code 915 FMI 14 or 31 is Inactive, Go to Step V

F
Purpose:Verify PTO 2 configuration with ServiceRanger.
  1. Key on.

  2. Connect ServiceRanger.

  3. Go To “Configuration”.

  4. Select “PTO”.

  5. Record "PTO 2" Current Value.

  • If “PTO 2” Current Value indicated “Disabled” and a PTO is properly installed and wired, select a “Hardwire Control Only” option and follow on-screen prompts. Go to Step V

  • If “PTO 2” Current Value indicates a “Hardwire Control Only” option and a PTO is properly installed and wired, Go to Step G

G
Purpose:Verify PTO 2 operation and Confirm feedback.
  1. Key on with engine running.

  2. Select transmission PTO 2 request switch to off (if necessary).

  3. Connect ServiceRanger.

  4. Go To “Data Monitor”

  5. From the “Default Parameter Files” tab, select “Transmission PTO”.

  6. Monitor 520536 – PTO Confirmation Voltage value. Record reading in table.

  7. Select transmission PTO 2 request switch to on.

  8. Monitor 520536 – PTO Confirmation Voltage value. Record reading in table.

  9. Compare reading(s) in table.

  • If readings are in range, no fault was found. The intermittent nature of the fault makes it likely that the problem is in the PTO, PTO 2 confirmation switch and/or wiring. Go to Step H

  • If readings are out of range, Go to Step H

ParameterRangeReading(s)
PTO 2 Off
520536 – PTO Confirmation Voltage4.5–5.5 V
PTO 2 On
520536 – PTO Confirmation Voltage0.0–0.5 V
H
Purpose:Verify Input/Output Package type with ServiceRanger.
  1. Key on with engine off.

  2. Connect ServiceRanger.

  3. Go To “Configuration”.

  4. Select “Calibrations” tab.

  5. Record "I/O Package" Current Value.

  • Based on I/O package configured refer to I/O circuit schematic indicated in table. Contact OEM or body builder for repair or replacement of PTO 2 Engage circuit. Go to Step V

    Note: PTO and circuit wiring are installed by OEM or body builder.

Fault Code 915: PTO 2 Engage
Package # and Description20-Way TCM Body Connector Pin(s)Component(s)
Input / Output Calibration Package 5 in TRIG2630: PTO 1 + PTO 23PTO2 Engage RelayPTO2 Fuse 2 AmpChassis Ground
Input / Output Calibration Package 23 and 26 in TRIG2630: PTO 1 + PTO 2 + Force Neutral and Hold Neutral + PTO 1 + PTO 2
Input / Output Calibration Package 34 in TRIG2630: PTO 1 + PTO 2 + Reverse Output
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.