Eaton Fuller Hybrid Fault Code 9 – Weak Battery 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. The Hybrid Control Module (HCM) is mounted to the transmission and contains all of the software to control both the hybrid power electronics as well as the transmission operation. The HCM main battery power is fused 12-volt feed that runs through the HCM 38-Way Vehicle Connector with the main ground wire returning to the battery negative terminal.
Fault Code 9 – Weak Battery Voltage Detection
The following preconditions must be met before the system detects the fault:
- HCM ignition voltage is greater than 7 volts and less than 16 volts.
- HCM System Battery Voltage Low Fault is Inactive.
Conditions to Set Fault Code Active
Conditions to Set Fault:
• FMI 14 is set when the HCM battery voltage drops below 9 volts for 10 seconds.
Fallback When Fault Code 9 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.
- 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. The HCM automatically clears a fault from history after that fault has been Inactive for 200 hours.
This fault code can be caused by any of the following:
- FMI 14
- Power Supply Harness to the HCM
- Low batteries or bad main power connection
- Charging system
Fault Code 9 – Weak Battery Voltage Test
Harness Front View
(HCM – Vehicle Interface 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.