Eaton Fuller Hybrid Transmission Fault Code 35 – J1939 Communication Link (TECU)
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. 1939 is a high-speed twisted pair 250K data link with one 120 ohm resistor at each end of the link. The Transmission Electronic Control Unit (TECU) is connected to the J1939 data link at the 38-Way Connector. This link is used to transmit information to the Hybrid Control Module (HCM) as well as communicate with or receive data from the other modules on the network such as the Electronic Control Unit (ECU).
Fault Code 35 – J1939 Communication Link (TECU) Detection
The following preconditions must be met before the system detects the fault:
- TECU ignition voltage is greater than 7 volts and less than 16 volts.
- TECU Battery Voltage Low fault is Inactive.
Conditions to Set Fault Code Active
- FMI 2 is set when the TECU loses communication with all modules on the J1939 data link for 5 or more seconds.
Fallback When Fault Code 35 is set the following conditions occur:
- Red “Service” light illuminates and an “F” flashes in the gear display.
- Fault is stored in TECU memory.
- The operation mode changes to AutoShift Fallback mode.
- If the fault sets at power up, the engine will not crank.
- If the fault sets while driving, the vehicle remains in current gear and the clutch opens when vehicle speed approaches idle.
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 2
- J1939 Data Link
Fault Code 35 – J1939 Communication Link (TECU) Test
Front Harness View
TECU – Vehicle Interface Connector
9-way Diagnostic 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.