Case IH 2310 – Transmission Control Unit (TCU): Upshift switch - voltage too low

The transmission controller monitors the electrical circuit for the upshift switch. This code is triggered when the input voltage from the switch circuit drops below the minimum expected threshold. This typically indicates an open circuit, a short to ground in the wiring harness, or an internal failure of the switch itself.

• Puma/Mid Range Magnum
• Puma series
• Maxxum series
• Steiger series
• T6000
• T7 series
• 8970A

1. 1

   Verify the battery voltage and alternator regulator output to ensure the transmission controller is receiving the correct base voltage (a low 5V/8V reference voltage can sometimes trigger false switch codes)

2. 2

   Use the tractor's Electronic Service Tool (EST) or the in-cab diagnostic monitor (H-Menu/PROG mode) to observe the upshift switch status. Cycle the switch to see if the state changes (e.g., from 0 to 1). If it stays at 0, the circuit is dead

3. 3

   Inspect the wiring harness and connectors between the shift lever (Multi-Function Handle/Multicontroller) and the transmission controller for chafed wires, loose pins, or signs of a short to ground

4. 4

   Disconnect the switch from the machine harness and use a multimeter to measure the resistance across the switch contacts (Common to Normally Open and Common to Normally Closed) while pressing and releasing the button to verify if the switch has failed internally

1. 1

   Power Down

   Turn off the tractor, apply the parking brake, and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Access the Switch

   Remove the necessary trim, console covers, or mounting plates on the main shift lever, Multicontroller (MFH), or range shift lever to access the upshift switch assembly.

3. 3

   Disconnect

   Unplug the electrical connector (often a 6-contact connector) linking the upshift switch to the machine's main harness.

4. 4

   Replace

   If the switch was diagnosed as faulty, remove the retaining hardware and extract the old switch. Install the new OEM switch into the lever housing.

5. 5

   Reassemble

   Reconnect the wiring harness, ensuring the connector is fully seated and locked. Reinstall all handle trim and console covers.

6. 6

   Restore Power and Clear Codes

   Reconnect the battery. Turn the key on, use the diagnostic monitor or EST to clear fault code 2310, and test the upshift function to confirm normal operation.