Case IH 5045 – Transmission Control Module (TCU) / Central Control Module (CCM): Ground speed PTO switch open/short to GND.

This code indicates a circuit fault where the controller detects that the electrical circuit for the Ground Speed Power Take-Off (PTO) switch is either open (broken wire/disconnected) or shorted directly to ground.

• Farmall
• MAXXUM T4E
• Case IH Maxxum Series (Tier 3)
• Case IH Puma Series
• Case IH MX / TG Series
• Case IH MXM / TM Series

1. 1

   Access the diagnostic menu (using special tool 380000843 or onboard display) to monitor the switch state on the diagnostic channel (e.g., Ch 28 or d48).

2. 2

   Monitor switch values: the controller should read 0 when the switch is depressed/engaged and 12000 when released/disengaged.

3. 3

   Inspect the wiring on the right-hand side top of the transmission.

4. 4

   Check the specific circuits for the Ground Speed PTO switch: Wire 2050AD (G) for PTO Supply / Dog Supply and Wire 2055 (B/W/S) for PTO Synchro Ground Speed Engaged.

5. 5

   Disconnect the switch and use a multimeter to check for continuity across the switch terminals when actuated.

6. 6

   Check the harness side for continuity to the controller (e.g., CN4A pin 23 or CN3B pin 33) and ensure neither wire is shorted to the tractor chassis (ground).

1. 1

   Safety First

   Park the tractor on a level surface, turn off the engine, and remove the key. Ensure all hydraulic pressure is relieved before working near the transmission.

2. 2

   Locate the Switch

   Access the right-hand side top of the transmission housing where the Ground Speed PTO switch and Axle Speed Sensor (C046) are located.

3. 3

   Disconnect the Harness

   Carefully unplug the electrical connector from the Ground Speed PTO switch. Inspect the connector for water ingress, corrosion, or pushed-out pins.

4. 4

   Repair or Replace

   If the wiring harness is chafed and shorting to the transmission case, repair the damaged section of wires 2050AD or 2055 and secure it with zip ties away from sharp edges. If the wiring is intact but the switch failed the continuity test, unthread the faulty switch from the transmission housing.

5. 5

   Install New Switch

   Thread the new Ground Speed PTO switch into the transmission housing and tighten to OEM specifications.

6. 6

   Reconnect and Clear Codes

   Plug the electrical connector back in. Turn the ignition on, enter the diagnostic menu, and clear the stored 5045 fault code from the EEPROM. Test the PTO engagement to verify the repair.