Eaton Fuller Hybrid Transmission Gear Engagement Test

Eaton Fuller Hybrid Transmission Gear Engagement Test Overview

Hybrid Control Module (HCM) normally commands the different gears shifts which are completed through the Transmission Electronic Control Unit (TECU). The HCM also controls the Electric Clutch Actuator (ECA), which changes the position of the clutch.
Note: This symptom-based test should only be performed if you were sent here from a diagnostic procedure and you have no Active fault codes.

Eaton Fuller Hybrid Transmission Gear Engagement Test Detection

The following symptoms may have been experienced:

  • Transmission does not engage a gear from neutral and warning tone sounds (solid “N” in gear display).
  • Transmission does not engage a gear from neutral (flashing gear in gear display). This symptom is addressed in the Front Box symptom test.
  • Transmission does not move from a stop (solid gear number in gear display).

This symptom can be caused by any of the following:

  • Transmission
  • Service Brake Switch
  • Boom/Outrigger Switch

Eaton Fuller Hybrid Transmission Gear Engagement Test

Component Identification:

Messages from the Body Controller to the HCM

Parameter Signal Value Meaning Description
520355 Prohibit Driving 0 Not Applied Body controller is requesting the HCM not allow gear arrangement form neutral.
1 Applied

Messages from the Engine, Chassis or Body Controller to the TECU

Parameter Signal Value Meaning Description
597 Brake Switch 0 Not Applied The ECU is confirming the current state of the service brake switch.
1 Applied

NOTE: Refer to the Eaton Hybrid Component and Connector Location for Connector Locations in MY08 Systems

NOTE: Refer to the Eaton Hybrid Component and Connector Location for Connector Locations in MY09 Systems.

Warnings & Cautions

Danger: Danger indicates you will be severely injured or killed if do not follow the indicated procedure.
Warning: Warning indicates an immediate hazard, which could result in severe personal injury if you do not follow the indicated procedure.
Caution: Caution indicates vehicle or property damage could occur if you do not follow the indicated procedure.

Note: Note indicates additional detail that will aid in the diagnosis or repair of a component/system.

Follow the specified procedures in the indicated order to avoid personal injury:

1. If the high-voltage cones are around the vehicle and the lockout is installed on the PEC, the only person that should be allowed to start the vehicle is the person who signed the lockout tag.
2. Before working on a vehicle or leaving the cab while the engine is running, you should place the shift lever in “N” set the parking brake, and block the wheels.
3. For safety reasons, always engage the service brakes prior to selecting gear positions from “N.”
4. Before starting a vehicle always be seated in the driver’s seat, select “N” on the shift control, and set the parking brakes.
5. In vehicles with ePTO, the engine and/or
Motor/Generator can start in ePTO mode. Never perform any maintenance or work on vehicle, while in this mode.
6. 12-Volt Battery positive (+) and negative (-) must be disconnected prior to any welding on any Hybrid equipped vehicle.

Caution: Follow the specified procedures in the indicated order to avoid equipment malfunction or damage.
Caution: Do not release the parking brake or attempt to select a gear until the air pressure is at the correct level.
Caution: To avoid damage to the transmission during towing place the shift lever in “N” and lift the drive wheels off the ground or disconnect the driveline.

High-Voltage Warnings & Cautions

  • Use CO2 or Dry Chemical Fire Extinguishers.
  • The high-voltage wiring is covered in orange insulation or convoluted tubing and marked with warning labels at the connectors.
  • All Eaton® Hybrid Diesel/Electric vehicles will be marked ‘Hybrid’ on the outside of the vehicle, along with the shift label on the dash.
  • Refer to OEM for specific location of chassis mounted hybrid components.
  • Do NOT cut into the orange high-voltage cables.
  • Do NOT cut into or open the PEC.
  • Do NOT cut into or open the DC/DC Converter.
  • Do NOT cut into or open the Inverter.

A buffer zone must be set up and high-voltage insulated rubber gloves (class 0 with leather protectors) are required prior to working on high-voltage. Failure to follow these instructions may result in severe personal injury or death.
The rubber-insulated gloves that must be worn while working on the high-voltage system are class 0 with leather protectors. The rubber gloves should be tested before EVERY use following the rubber insulation gloves testing procedure found in “Diagnostic Tools/Service Publications” on page 6. Failure to follow these instructions may result in severe personal injury or death.
Before inspecting or working on any high-voltage cables or components the “High-Voltage Service Shutdown and Power-Up Procedure” on page 4 should be followed. Failure to follow these instructions may result in severe personal injury or death.
The Lockout and Tagout devices should only be removed by the technician that placed the Lockout and Tagout devices on the vehicle. Failure to follow these instructions may result in severe personal injury or death.
High-voltage rubber insulated gloves (class 0 with leather protectors) must be worn when working on any
high-voltage cables. The “High-Voltage Service Shutdown and Power-Up Procedure” on page 4 must be followed prior to removing any high-voltage cables. Failure to follow these instructions may result in severe personal injury or death.
High-voltage cables and wiring are orange and contain a warning label at the connectors. High-voltage components are marked with a label. High-voltage rubber insulated gloves (class 0 with leather protectors) must be used when working on any of these components. Failure to follow these instructions may result in severe personal injury or death.

High-Voltage Service Shutdown Procedures

High-Voltage Service Shutdown and Power-Up Procedure1. Follow “High-Voltage Work Area” procedure.
2. Locate the red PEC Service Switch on the front of the PEC and push switch off.
3. Remove the Service Switch Cover and install the Lockout Bracket (J48506).
4. Fasten tag to the Lockout Bracket.
5. Ensure the PEC Service Switch can not move from the off position.
6. Allow the system to set for a minimum of 5 minutes to discharge high voltage.
7. Connect ServiceRanger and view the Data Monitor PID 116 called “High-Voltage Battery Potential.” Use SPN 520323 for J1939 connection “Battery Voltage RB” (Relay Box).
8. The voltage should be 30 volts or less. If the voltage is above 30 volts, do not work on the vehicle and contact Eaton® at 1-800-826-HELP (4357).
9. Turn ignition key off and proceed to repair or troubleshooting step.
Note: The voltage drops to zero when the key is off.

High-Voltage Service Power-Up Procedure

1. Install all high-voltage connectors into their locked positions.
2. If you are the person working on the vehicle, remove the Lockout Bracket and tag.
3. Reinstall the Lockout Bracket over the Service Switch.
4. Pull the Service Switch out and let vehicle set for 2 minutes.
5. Start vehicle when appropriate.

Eaton Hybrid Component and Connector Location

Eaton Hybrid Component and Connector Locations MY08 Systems

Eaton Hybrid Component and Connector Location MY09 Systems

Eaton Hybrid Component and Connector Locations MY09 Systems

STEP 1. Visually observe the gear display after power up.

  1. You should only perform this symptom test if you were sent here from a diagnostic procedure and you have no Active fault codes.
  2. Press N on the Push Button Shift Control.
    • If “N” is present on the gear display, go to Step 2.
    • If “N” is not present on the gear display, refer to the diagnostic procedure for the correct symptom-based test to perform.

STEP 2. Visually observe the gear display when placing the transmission into Drive.

  1. Key on.
  2. Start engine.
  3. Press Service Brake and select D.
    • If gear display shows “N” and a warning tone sounds, go to Step 4.
    • If gear display shows a flashing gear with no arrows, go to “Front Box Test”.
    • If gear display shows a solid gear, but vehicle does not move, go to Step 3.

STEP 3. Confirm the proper parameter configuration to prohibit driving.

  1. Key on.
  2. Connect ServiceRanger and view the following:
    • Data Monitor parameter PID 154 “Prohibit Driving”
      • “Prohibit Driving” reads 0 (allow driving).
      • Contact Eaton at 1-800-826-HELP [4357].
      • “Prohibit Driving” reads 1 (prohibit driving).
      • Ensure boom and outriggers are fully retracted. Contact your OEM for repair procedures, then go to Step 5.

STEP 4. Verify proper brake status signal.

  1. Key on.
  2. View the following Data Monitor parameter while pressing the Service Brake.
    • SPN 597 “Service Brake Status”
      • If the Service Brake Switch status is pressed when you apply the brakes, contact Eaton at 1- 800-826-HELP [4357].
      • If the Service Brake Switch does not change status, repair Service Brake wiring or switch. Contact your OEM for repair procedures then go to Step 5.

STEP 5. Verify repair.

  1. Key off.
  2. Reconnect all connectors.
  3. Place Shift Control into neutral.
  4. Key on.
    • If the transmission engages a gear and moves from a stop, test is complete.
    • If the transmission does not engage a gear or move from a stop, go to Step 1. Find error in testing.

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