Eaton Fuller Hybrid Transmission Fault Code 112 – Inverter Voltage
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 Inverter is connected to the Power Electronics Carrier (PEC) through a high-voltage DC cable, which supplies 340 volts from the batteries. During operation, the Inverter monitors the input voltage to determine an over or under voltage concern.
Fault Code 112 – Inverter Voltage Detection
The following preconditions must be met before the system detects the fault:
- Inverter 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 4 is set when the Inverter input voltage measured at the capacitor is less than 200 volts for 1 second, while the main relays in the Relay Box are on.
- FMI 3 is set when the Inverter input voltage measured at the capacitor is greater than 435 volts for 0.05 MS.
Fallback When Fault Code 112 is set the following conditions occur:
- Amber “Check Hybrid” light illuminates.
- Fault is stored in Hybrid Control Module (HCM) memory.
- Inverter shuts high-voltage system off.
- HCM continues to control the hybrid vehicle in a diesel-only mode.
- Transmission defaults start gear to 1st.
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 1, 3, 4
- DC High-Voltage Cable
Fault Code 112 – Inverter Voltage Test
High-Voltage DC Connector to PEC
High Voltage DC Connector View Yazaki Connector
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.