Eaton Fuller Hybrid Transmission Front Box Test
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.This symptom-driven test is performed if a dash “-” or flashing gear is displayed on the gear display, and there are no Active or Inactive codes. Turn key on and watch the gear display. If the gear display shows a dash “-” constantly, the Transmission Electronic Control Unit (TECU) was not able to confirm Front Box control. If the transmission displays a flashing gear when a forward or reverse mode is selected, the transmission is not able to engage the gear position.
Note: This symptom-based test should only be performed if directed here from the Diagnostic Procedure and there are no Active fault codes.
Front Box Test Detection
The following preconditions must be met before the system detects the fault:
- Power up no crank and gear display shows a dash “-”.
Transmission does not engage a gear from neutral (flashing gear number is gear display).
Fallback When Front Box Test is set the following conditions occur:
There is no fallback mode for this symptom; however, the vehicle may do either of the following: not crank if the dash “-” is present or not engage a gear if the flashing gear is present when a non-neutral gear is selected.
- Low power to Gear Select motor
- Electric Shifter
- Gear Select Sensor
- Yoke/Clutch/Main Shaft
- Shift Bar Housing
- Dragging Clutch
- Torque Locked in Gear