Eaton Fuller Hybrid Transmission Fault Code 97 – PTO Engagement
Fault code for Eaton Hybrid Drive Systems models (MY08) EH-8E306A-U, EH-8E306A-UPG, EH-8E306A-UP, EH-8E306A-CD, EH-8E306A-T, EH-6E606B-CD, (MY09) EH-8E406A-U/P, EH-8E406A-UP, EH-8E406A-UPG, EH-8E406A-CD, EH-8E406A-CDG, EH-8E406A-CDR, EH-8E406A-T, EH-6E706B-CD, EH-6E706B-P and EH-6E706B-UPG. Read below to learn how to test, clear and fix fault code errors for your Freightliner, Mack, Peterbilt, Kenworth, Volvo, International, and heavy-duty truck and equipment.
The PTO is an optional installation on the transmission. The PTO is an electric-over-air unit. The PTO is controlled either by the Hybrid Control Module (HCM) or the Body Controller. Note: This fault is only set if the HCM is directly wired to thePTO. This can be determined by checking the HCM configuration. The “PTO Feedback” will read analog.
The HCM controlled PTO energizes the electric solenoid and air pressure engages the PTO. The PTO feedback signal is a 12-volt signal. Less than 1 volt indicates the PTO is engaged, and greater than 3 volts indicates the PTO is disengaged.
Body Controller Operated PTO:
The Body Controller operated PTO energizes the electric solenoid and air pressure engages the PTO. When the user selects the ePTO option the Hybrid Control Module (HCM) sends a request to the Body Controller to activate the PTO. When the PTO is engaged, the Body Controller sends back a confirmation message.
Note: When determining which module is controlling the PTO, connect ServiceRanger and view the “Configurations” screen. Under the “Hybrid Control Module” is a listing for PTO Feedback, which is either Analog Controlled (HCM), or J1939 Controlled (Body Controller). The “PTO Engaged” parameter provides the input from the HCM or the Body Controller on the current state of the PTO. This parameter is available in ServiceRanger under the Data Monitor “Hybrid ePTO” list.
Fault Code 97 – PTO Engagement Detection
The following preconditions must be met before the system detects the fault:
- Hybrid Control Module (HCM) ignition voltage is greater than 7 volts and less than 16 volts.
Note: When troubleshooting an Inactive code refer to the Product Diagnostic Mode (PDM)
Conditions to Set Fault Code Active
- FMI 3 is set when the HCM detects a short to the VBATT in the PTO control circuit.
- FMI 4 is set when the HCM detects a short to ground in the PTO control circuit.
- FMI 5 is set when the HCM detects an open in the PTO control circuit.
- FMI 7 is set when the HCM detects the transmission is in neutral and, if after 8 seconds from requesting PTO mode the PTO engaged signal reads “Disengaged.”
- FMI 14 is set when the ePTO option on the Push Button Shift Control is selected and the HCM detects the transmission is not in neutral based on output shaft speed.
Fallback When Fault Code 97 is set the following conditions occur:
- Fault is stored in HCM memory.
- If the PTO is engaged and the fault occurs, the PTO remains engaged until the ePTO request changes, or the air pressure drops below a
- If the PTO is not engaged the ePTO light flashes on the Push Button Shift Console.
Conditions to Set Fault Code Inactive
Only Inactive faults can be cleared from the Transmission Electronic Control Unit (TECU) or HCM history using ServiceRanger. The TECU automatically clears the faults from history after 200 hours and the HCM automatically clears the faults from history after the fault has been Inactive for 200 hours.
This fault code can be caused by any of the following:
- FMI 7:
- PTO Air Solenoid
- Low air pressure
- PTO control circuit wires
- PTO feedback circuit
- PTO Ball Switch
Fault Code 97 – PTO Engagement Test
1. Hybrid Control Module (HCM)
2. Nut (3)
3. 38-Way System Connector Plug-in
4. 38-Way Vehicle Connector Plug-in
5. Mounting Plate
NOTE: Refer to the Eaton Hybrid Component and Connector Location for Connector Locations in MY08 Systems