Eaton Fuller Hybrid Transmission Fault Code 122 – APG UNIT 1 Output
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. Read below to learn how to test, clear and fix fault code errors for your Freightliner, Mack, Peterbilt, Kenworth, Volvo, International, and heavy-duty truck and equipment. The Auxiliary Power Generator (APG) is a 5kW/5kVA DC/AC Inverter connected to the high voltage DC bus of the Eaton Hybrid electric vehicle system. It generates 60 Hz single-phase 120V AC power for utility applications.
Fault Code 122 – APG UNIT 1 Output Detection
The following preconditions must be met before the system detects the fault:
- APG Inverter needs to be operating.
Note: When troubleshooting an Inactive code refer to the Product Diagnostic Mode (PDM)
Conditions to Set Fault Code Active
- FMI 6 is set when multiple over current events are detected.
- FMI 14 is set when the UPS has detected abnormally low impedance placed on its output.
- FMI 15 is set when the UPS output current limit (calculated or measure) has been exceeded for the longer than allowed by the internal time limit.
Fallback When Fault Code 122 is set the following conditions occur:
- Amber “Check Hybrid” light illuminates.
- Fault is stored in Hybrid Control Module (HCM) memory.
- APG shuts down.
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 6, 15
- Short phase to ground in harness
- Output device causing surge
- Power Panel
- FMI 14
- Component drawing excessive current
Fault Code 122 – APG UNIT 1 Output Test
Harness Front View
(HCM – Hybrid System Interface Connector)
Deutsch 4-way OEM connector
NOTE: Refer to the Eaton Hybrid Component and Connector Location for Connector Locations in MY08 Systems