Eaton Fuller Hybrid Fault Code 10 – Low Battery Voltage (HCM)
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. The Hybrid Control Module (HCM) is mounted to the transmission and contains the software that controls both the hybrid power electronics as well as the transmission operation. The HCM main battery power is a fused, 12-volt feed and runs through the HCM 38-Way Vehicle Connector with the main ground wire returning to the battery negative terminal.
Fault Code 10 – Low Battery Voltage (HCM) 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.
Conditions to Set Fault Code Active
Conditions to Set Fault:
• FMI 4 is set when the HCM battery voltage drops below 7 volts for more than 1 second.
Fallback When Fault Code 10 is set the following conditions occur:
• Amber “Check Hybrid” light illuminates.
• Red “Hybrid Stop” lamp will display if there are additional fault codes caused by the low or weak voltage. This feature was added with HCM Software 1107 and higher.
• Fault is stored in HCM memory.
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 4
- Power Supply Harness to the HCM
- Low batteries or bad power connection
- Charging system
Fault Code 10 – Low Battery Voltage (HCM) Test
Harness Front View
(HCM – Vehicle Interface Connector)
Typical Relay Switch
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.