New Holland TRANS 62 – Transmission Controller: System pressure solenoid is shorted to B+

The control module has detected that the voltage on the energize circuit for the transmission system pressure solenoid is above normal, indicating a short circuit directly to the battery positive (+12V).

• T7 series
• T8 series (T8030, T8050, T8.275 - T8.390)
• T9 series
• Magnum series (235-340)
• Steiger
• Quadtrac
• W190B
• W270B

1. 1

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

2. 2

   Inspect the wiring harness running from the Transmission Controller to the system pressure solenoid for rubbed, chafed, or melted wires bridging the circuit to a constant +12V source

3. 3

   Disconnect the electrical connector (C436 or C521) at the solenoid and use a multimeter to test the harness-side connector for a short to B+ (Battery Positive)

4. 4

   Test the solenoid coil for an internal short (if the harness tests good but the code persists when plugged in, the solenoid has failed internally)

5. 5

   Test the Transmission Controller (ECM) for an internal fault keeping the circuit energized (unlikely, but possible if wiring and solenoid test perfectly)

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the battery to prevent accidental shorting during repair.

2. 2

   Access the Valve Block

   Locate the priority/regulator valve on the transmission housing.

3. 3

   Disconnect Wiring

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

4. 4

   Harness Repair (If Applicable)

   If your diagnostic tests revealed a short in the wiring harness, splice and repair the damaged section of the wire, or replace the connector pigtail if the short is inside the plug.

5. 5

   Replace Solenoid (If Applicable)

   If the solenoid is internally shorted, remove the retaining hardware holding the system pressure solenoid assembly in the regulator valve block. Extract the old solenoid and install the new OEM replacement.

6. 6

   Reassembly

   Reconnect the electrical connector to the solenoid. Reconnect the battery.

7. 7

   Clear Codes

   Power on the machine and use the onboard display or the CNH Electronic Service Tool (EST) to clear the TRANS 62 / 2806 diagnostic code.

8. 8

   Operational Test

   Start the tractor and verify that transmission system pressures are normal and the fault code does not return.