Fault code for Eaton Hybrid Drive Systems models (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 High-Voltage Relays are located inside the Power
Electronics Carrier (PEC) in the Relay Box unit. There is one Pre-Charge Relay on the positive side, an additional relay on the positive, and on the negative for a total of three relays. These relays are normally open when the system is off. The relays are controlled through the Inverter.
Fault Code 116 – High Voltage Relays Fault 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 3 is set when a short to 12 volts is detected on the control side of a high-voltage relay.
- FMI 4 is set when a short to ground is detected on the control side of a high-voltage relay.
- FMI 5 and FMI 10 are set when an open circuit is detected on the control side of a high-voltage relay.
- FMI 7 and FMI 14 are set when the main negative relay is on and the inverter capacitor voltage decrease is less than 10-volts / 5 seconds when initial capacitor voltage was greater than 200 volts.
Fallback When Fault Code 116 is set the following conditions occur:
- Amber “Check Hybrid” light illuminates.
- Fault is stored in Hybrid Control Module (HCM) memory.
- The hybrid system will be offline.
- Transmission defaults start gear to 1st in diesel-only mode.
Conditions to Set Fault Code Inactive
Only inactive faults can be cleared from the TECU or HCM history using ServiceRanger. The TECU automatically clears the faults from history after 200 hours. The HCM automatically clears a fault from history after that fault has been Inactive 200 hours.
This fault code can be caused by any of the following:
- FMI 3, 4, 5, 7, 10, 14
- Voltage Feedback wire from DC/DC Converter to HCM
- FMI 4
- Relay Box
- Inertia Switch
- Vehicle Wiring Harness between the Inverter and the PEC
- Main High-Voltage Service Fuse is blown or missing
- DC High-Voltage Cable Interlock
- PEC Red Button Service Switch