New Holland TRANS 2806 – Transmission Control Module (TCU / TRANS): System pressure solenoid is shorted to B+

The transmission controller has detected that the voltage in the system pressure solenoid circuit is above normal, typically caused by a failed solenoid coil or a wiring harness shorting to a power source.

• T8.xxx Series
• T8010
• T8020
• T8030
• T8040
• T8050
• T8.275
• T8.300
• T8.330
• T8.360
• T8.390
• Magnum 235 - 340 (Series 4)
• Steiger series

1. 1

   Locate the system pressure solenoid valve assembly on the priority/regulator valve block

2. 2

   Disconnect the system pressure solenoid connector (identified as C039, C436, or C521 depending on the model year)

3. 3

   Measure the resistance of the solenoid coil between cavity A and cavity B on the solenoid side

4. 4

   Verify the resistance is approximately 5.9 to 6.5 ohms at 27 degrees Celsius (80 degrees Fahrenheit). If higher or out of bounds, the solenoid has an internal short and must be replaced

5. 5

   If the resistance is within the specified range, check the tractor wiring harness between the solenoid connector and the transmission controller for a short to battery voltage (B+) or wire damage

1. 1

   Power Down

   Turn off the tractor, remove the key, and ensure the hydraulic system is depressurized.

2. 2

   Locate the Valve Block

   Access the priority/regulator valve block where the primary hydraulic power system distributes flow.

3. 3

   Disconnect Wiring

   Unplug the 2-cavity electrical connector from the system pressure solenoid.

4. 4

   Remove the Solenoid

   Unthread/remove the faulty system pressure solenoid assembly from the priority/regulator valve block.

5. 5

   Install the New Part

   Install the replacement system pressure solenoid and torque to OEM specifications.

6. 6

   Reconnect and Clear

   Reconnect the wiring harness. Turn the key on and use the tractor's diagnostic monitor or an EST (Electronic Service Tool) to clear the TRANS 2806 fault code.

7. 7

   Test

   Start the tractor and verify that full regulated pressure is maintained to the transmission clutches without the code returning.