Eaton Fuller Hybrid Transmission Fault Code 59 – J1939 Communication Link (HCM)

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. J1939 is a high-speed twisted pair 250K data link with one 120 ohm resistor at each end of the link. The Hybrid Control Module (HCM) is connected to the J1939 data link at the 38-Way Connector. This link is used to transmit or receive operation information from other modules on the network like the Transmission Electronic Control Unit (TECU) or Electronic Control Unit (ECU).

Fault Code 59 – J1939 Communication Link (HCM) Detection

The following preconditions must be met before the system detects the fault:

  • Hybrid Control Module (HCM) ignition voltage is greater than 7 volts and less than 16 volts.

Note: When troubleshooting an Inactive code refer to the Product Diagnostic Mode (PDM)

Conditions to Set Fault Code Active

  • FMI 2 is set in Product Diagnostic Mode (PDM) and occurs when the HCM loses communication with any other module on the J1939 Data Link for 3
    consecutive messages.
  • FMI 9 is set when the HCM loses communication with all modules on the J1939 data link for 30 consecutive messages or greater.

Fallback When Fault Code 59 is set the following conditions occur:

  • Amber “Check Hybrid” and red “Stop Hybrid” lights do not display, since the lights are driven over the J1939 Data Link.
  • Fault is stored in HCM memory.
  • Operation mode changes to “AutoShift Only” mode.
  • If the fault sets at power up, the engine will not crank.
  • If the fault sets while driving, the vehicle will shift, however; when the vehicle stops the clutch opens and remains open.
  • Electric Motor/Generator Assist and Regeneration are disabled; however, the high-voltage relays remain powered.
  • Red “Service” light and an “F” flashing in the gear display may appear due to the Active fault code 24, 35, or 36.

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
    • HCM

Fault Code 59 – J1939 Communication Link (HCM) Test

Component Identification:

HCM - Hybrid System Interface Connector

Harness Front View
(HCM – Hybrid System Interface Connector)

Eaton Fuller transmission 9 pin diagnostic connector

9 Pin 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.

HCM 9 pin diagnostic connector location for Eaton Fuller transmission

STEP 1. Check for Active or Inactive fault code status.

  1.  Retrieve Active fault codes and FMIs with ServiceRanger using the 9-Way Diagnostic Connector.
  2. Key on.
  3. Select the “Vehicle Components” screen and view the various modules that are reporting on the J1939 link:
    • If the HCM is not reporting on J1939 but the TECU is listed, go to Step 2.
    • If the HCM and TECU are not reporting on J1939, go to Step 3.

STEP 2. Verify continuity of Vehicle Harness circuits.

  1. Key off
  2. Disconnect negative battery cable.
  3. Disconnect HCM Harness 38-way connector.
  4. Measure resistance between HCM Harness 38-Way Connector Pin 2 and Pin 3:  .
    Note: Make sure the Volt/Ohm Meter is on the proper scale (around 200 ohm scale)

    • If resistance between Pin 2 and Pin 3 is between 50–70 ohms, replace the Hybrid Control Module (HCM), then go to Step 5.
    • If resistance is outside of range, repair J1939 Data link Harness, then go to Step 5.

STEP 3. Verify continuity of Diagnostic Connector J1939 circuits.

  1. Key off.
  2. Measure the resistance between Pin C and Pin D on the 9-Way Diagnostic Connector:
    • If resistance between Pin C and Pin D is 50–70 ohms, go to Step 4.
    • If resistance is 70 ohms or greater, one or more of the terminating resistors on the J1939 Data Link Harness is missing, out of range, or there is an open in the link. Repair the OEM J1939 Data Link Harness, then go to Step 5.
    • If resistance is 50 ohms or less, there is an additional terminating resistor present. Repair the OEM J1939 Data Link Harness, then go to Step 5.

STEP 4. Verify continuity of Diagnostic Connector J1939 circuits.

  1. Key off.
  2. Measure resistance between Pin C and ground on the 9-Way Diagnostic Connector:
    • If resistance between Pin C and ground is 10K ohms or greater, attempt to communicate with another vehicle and ensure ServiceRanger is working. If ServiceRanger fails to communicate with another vehicle, call 1- 800-826-HELP (4357).
    • If resistance is outside of range, repair J1939 Data link Harness for a short to ground, then go to Step 5.

STEP 5. Verify repair.

  1. Key off.
  2.  Key on.
  3. Clear codes, see  Clear Inactive Faults.
  4. Reconnect all connectors and the negative battery cable.
  5. Drive the vehicle and attempt to reset the code.
  6. Check for codes, see View Active and Inactive Faults.
    • If no codes, test is complete.
    • If fault Code 59 appears, find error in testing, go to Step 1.
    • If a code other than 59 appears, see Fault Code Index List.

Any transmission part you need we have it! Same day shipping available, worldwide.

NEED FREE SUPPORT FROM ONE OF OUR EXPERTS?

CALL NOW
EMAIL US