Fault Code 912: Split Shaft PTO Engage
J1939: SA 3 SPN 3458 FMI 3, 4, 5, 6, 7, 12, 14, 31
Overview
The Endurant XD Series 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 XD Driver Instructions TRDR0960 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 for recommended PTO circuit wiring diagrams.
Detection
The TCM monitors the Split Shaft PTO Engage J1939 messages or the hardwired Split Shaft PTO 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: Split Shaft PTO Engage circuit output signal shorted to power for 5 seconds.
FMI 4 – Voltage Below Normal or Shorted Low: Split Shaft PTO Engage circuit output signal shorted to ground for 5 seconds.
FMI 5 – Current Below Normal or Open Circuit: Split Shaft PTO Engage circuit open for 5 seconds.
FMI 6 – Current Above Normal or Grounded Circuit: Split Shaft PTO Engage circuit output current out of range for 5 seconds.
FMI 7 - Mechanical System Not Responding: Split Shaft PTO Engage commanded, but Split Shaft PTO Confirm message or signal not received.
FMI 12 – Bad Intelligent Device: TCM had 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
- Split Shaft PTO Mode prohibited
Conditions to Set Fault Code Inactive
FMI 3: Split Shaft PTO Engage circuit not shorted to power for 10 seconds.
FMI 4: Split Shaft PTO Engage circuit not shorted to ground for 10 seconds.
FMI 5: Split Shaft PTO Engage circuit not open for 10 seconds.
FMI 6: Split Shaft PTO Engage circuit output current in range for 10 seconds.
FMI 7: Split Shaft PTO 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 - Split Shaft PTO Engage Circuit
- Shorted to power, shorted to ground, or open circuit
FMI 7:
- Vehicle Harness - Split Shaft PTO Confirm Circuit
- Open circuit
- Vehicle Components - Split Shaft PTO 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 912 Troubleshooting
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 912 is Inactive and there are other Active vehicle or transmission fault codes, troubleshoot all Active fault codes. Go to Step V
If Fault Code 912 FMI 3, 4, 5, or 6 is Active, Go to Step B
If Fault Code 912 FMI 3, 4, 5, or 6 is Inactive, the intermittent nature of the fault makes it likely that the problem is in the Split Shaft PTO Engage circuit. Go to Step D
Note: PTO and circuit wiring are installed by OEM or body builder.
If Fault Code 912 FMI 7 is Active or Inactive, Go to Step C
If Fault Code 912 FMI 12 is Active, replace Transmission Control Module (TCM). Go to Step V
If Fault Code 912 FMI 12 is Inactive, Go to Step V
If Fault Code 912 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 912 FMI 14 or 31 is Inactive, Go to Step V
Key on.
Connect ServiceRanger.
Go To “Configuration”.
Select “PTO”.
Record "Split Shaft PTO Configuration" Current Value.
If "Split Shaft PTO Configuration" Current Value indicates “Disabled” and Split Shaft PTO circuit is properly installed and wired, select a Stationary or Mobile Analog (hardwired) option and follow on-screen prompts. Go to Step V
If "Split Shaft PTO Configuration" Current Value indicates a Stationary or Mobile Analog (hardwired) option and the Split Shaft PTO Request circuit is properly installed and wired, Go to Step D
Key on with engine running.
Select transmission Split Shaft PTO request switch to off (if necessary).
Connect ServiceRanger.
Go To “Data Monitor”.
From the “Default Parameter Files” tab, select “Transmission PTO”.
Monitor 520536 - PTO Confirmation Voltage value. Record reading in table.
Select transmission Split Shaft PTO request switch to on.
Monitor 520536 - PTO Confirmation Voltage value. Record reading in table.
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 Split Shaft PTO, Split Shaft PTO confirmation switch and/or wiring. Go to Step D
If readings are out of range, Go to Step D
| Parameter | Range | Reading(s) |
|---|---|---|
| SSPTO Off | ||
| 520536 – PTO Confirmation Voltage | 4.5–5.5 V | |
| SSPTO On | ||
| 520536 – PTO Confirmation Voltage | 0.0–0.5 V | |
Key on with engine off.
Connect ServiceRanger.
Go To “Configuration”.
Select “Calibrations” tab.
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 Split Shaft PTO Engage circuit. Go to Step V
Note: Split Shaft PTO and circuit wiring are installed by OEM or body builder.
| Fault Code 912: SSPTO Engage | |||||
|---|---|---|---|---|---|
| Package # and Description | 20-Way TCM Body Connector Pin(s) | Component(s) | |||
| Input / Output Calibration Package 20 of TRIG2630: Split Shaft PTO | 3 | SSPTO Engage Relay | SSPTO Fuse 2 Amp | Chassis Ground | |
| I Input / Output Calibration Package 21 of TRIG2630: PTO 1 + Split Shaft PTO | |||||
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 912 sets Active, Go to Step A
If a fault code other than 912 sets Active, troubleshoot per the Fault Code Isolation Procedure Index.