Case IH 56087 – Transmission Controller (TRANS): Trans Neutral Latch Relay Coil circuit is shorted to 12 volts when commanded ON.

The transmission controller has commanded the transmission neutral latch relay (Relay #17) to turn on, but it detects that the voltage on the low side of the relay coil is higher than expected. This indicates a short circuit to a 12-volt power source. The neutral latch relay is responsible for controlling the power supply to the lockup valve group and the neutral relay.

• STX Steiger
• Case IH Puma Series
• Puma 115
• Puma 125
• Puma 140
• Puma 155
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225
• Case IH Steiger Series
• Case IH MX Magnum Series
• Case IH CS 150

1. 1

   Check if the neutral latch relay coil (Relay #17) is internally shorted

2. 2

   Inspect the wiring harness between the relay coil and the transmission controller for a short to 12V power

3. 3

   Verify if the transmission controller itself has failed

1. 1

   Clear the Code

   Clear fault code TRANS 56087 from the system.

2. 2

   Swap the Relay

   Locate the transmission neutral latch relay (Relay #17 in the fuse/relay panel) and replace it with a new or known-good relay.

3. 3

   Test Operation

   Start the tractor and let it run for several minutes. Shut down the tractor and check the fault codes again.

4. 4

   Evaluate

   If the code does not return, the original transmission control relay had failed internally. The repair is complete. If fault code TRANS 56087 is recorded again, proceed to the next step.

5. 5

   Test the Relay Manually

   If no spare is available, unplug Relay #17 and use a multimeter to measure the resistance between pin 1 and pin 2 of the relay to check for an internal coil short.

6. 6

   Trace the Wiring

   If the relay is good but the code persists, trace the wiring harness between the relay socket and the transmission controller. Look for rubbed or melted wire insulation causing a short to a 12-volt power source. Repair any damaged wiring.

7. 7

   Controller Check

   If both the relay and the wiring harness test good, the transmission controller has likely failed and will need to be tested or replaced.