Case IH 137 – Transmission Controller (TRANS): Governor CAN bus off line

The Transmission Controller has lost Controller Area Network (CAN) communication with the Engine Governor (Engine ECU). Without this communication, the transmission cannot receive critical engine speed and torque data, which often results in the transmission controller dropping offline, blowing fuses, and preventing the tractor from moving.

• STX Steiger
• Case IH Steiger Series
• Case IH Quadtrac Series

1. 1

   Check transmission fuses (specifically Fuse #39 on Steiger models) to see if it is blown, which indicates a short to ground on the transmission controller's power circuit.

2. 2

   Isolate the park brake solenoid by disconnecting it (or pulling the park relay) and attempting to shift the tractor into gear. If the fuse does not blow with the solenoid unplugged, the solenoid is the culprit.

3. 3

   Inspect the wiring harness between the cab connector and the Bottom of Brake (BOB) switch, as well as the driveline speed sensor wires, for chafing or shorts against the chassis.

1. 1

   Locate the Short

   Access the transmission valve block and locate the park brake solenoid (typically located behind the right-side service door on Steiger models).

2. 2

   Unplug the Solenoid

   Disconnect the 2-pin electrical connector to the park brake solenoid.

3. 3

   Test the Circuit

   Replace the blown transmission fuse in the cab. Turn the key on and attempt to shift the tractor out of neutral.

4. 4

   Replace the Solenoid

   If the tractor shifts without blowing the fuse and the controller stays online, the park brake solenoid coil has lost its magnetization/failed internally. Remove the retaining nut on the solenoid valve, slide the old coil off, and install the new park brake solenoid coil.

5. 5

   Repair Wiring (If Applicable)

   If the fuse still blew during step 3, trace the wiring from the park brake pressure switch and Bottom of Brake (BOB) switch back to the cab connector. Repair any chafed or exposed wires using a CAN bus/wiring repair kit.

6. 6

   Clear Codes

   Reconnect all components, ensure the transmission fuse is intact, and cycle the key to clear the TRANS 137 fault code. Test drive the machine to verify the park brake releases and the transmission shifts normally.