Eaton Fuller Hybrid Transmission Fault Code 18 – ECA Communication
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 Electric Clutch Actuator (ECA) controls the position of the clutch assembly. The ECA communicates with the Hybrid Control Module (HCM) over the proprietary Controller Area Network (CAN) data link to change position, show faults or transmit other operation information.
Fault Code 18 – ECA Communication 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.
- ECA ignition voltage is greater than 8.5 volts.
- HCM CAN data link error is Inactive.
Conditions to Set Fault Code Active
Conditions to Set Fault:
• FMI 9 is set when the ECA loses communication on the CAN Data Link for 2 seconds.
Fallback When Fault Code 18 is set the following conditions occur:
- Red “Stop Hybrid” light illuminates.
- Fault is stored in HCM memory.
- ECA maintains current clutch position or moves to the last position commanded by the HCM. Upon approaching idle, the clutch opens and remains in this state.
- If the fault occurs at power up, the vehicle does not crank.
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 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 2, 9
- CAN Data Link from the ECA to the link
Fault Code 18 – ECA Communication Test
Harness Front View
(HCM – Vehicle Interface Connector)
ECA 8-Way Harness 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.