Eaton Fuller Hybrid Fault Code 12 – Improper TECU Configuration
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 Transmission Electronic Control Unit (TECU) is mounted to the transmission and contains all of the software to control the transmission operation; however, the Hybrid Control Module (HCM) controls the operation of the TECU during hybrid operation.
Fault Code 12 – Improper TECU Configuration Detection
The following preconditions must be met before the system detects the fault:
- TECU is powered and ignition voltage is greater than 7 volts and less than 16 volts.
Conditions to Set Fault Code Active
- FMI 13 is set when the TECU is not reading valid information from memory, including the transmission table and calibration values within 1 second of power up.
Fallback When Fault Code 12 is set the following conditions occur:
- Red “Service” light illuminates and “F” flashes in the gear display.
- 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 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 13
- Improper TECU configuration software
Fault Code 12 – Improper TECU Configuration Test
NOTE: Refer to the Eaton Hybrid Component and Connector Location for Connector Locations in MY09 Systems.