Case IH P41 – Electronic Management Unit (EMU): PTO Fender Switch Relay Coil Short To Ground (P41) / Msg1 Message, Data Valid But Above Normal Range (T41)

Code P41 indicates an electrical fault in the rear Power Take-Off (PTO) circuit where the ground circuit for the fender-mounted PTO switch relay coil is shorted to chassis ground. Code T41 indicates a CAN communication error where the Msg1 data packet value is higher than programmed normal operating parameters.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• TM120
• TM130
• TM140
• TM155
• TM175
• TM190

1. 1

   [For Code P41] Turn the key switch to the OFF position.

2. 2

   [For Code P41] Locate the PTO fender switch relay (often designated as relay 'kx' in the manual).

3. 3

   [For Code P41] Remove the relay and bench-test its operation using a multimeter to check for internal shorts across the coil pins.

4. 4

   [For Code P41] Disconnect the Electronic Management Unit (EMU) Connector designated as C105.

5. 5

   [For Code P41] Using a multimeter, check wire C105–12 (Orange/Light Green wire) for continuity to ground. If there is continuity, the wire is shorted against the chassis.

6. 6

   [For Code T41] Check the CAN bus wiring harness for high resistance, corrosion at the connectors, or voltage irregularities that could cause data to spike out of range.

7. 7

   [For Code T41] Verify the ground connections for the EMU and the Digital Instrument Cluster.

1. 1

   Replace the relay

   [For Code P41] If the bench test of the PTO fender switch relay shows it is faulty (internally shorted), replace the relay.

2. 2

   Trace wire C105-12

   [For Code P41] If the relay operates correctly, the fault lies in the wiring harness. Trace wire C105-12 (Orange/Light Green) from the EMU to the fender switch relay block.

3. 3

   Locate the short

   [For Code P41] Locate the chafed or melted section of the wire where it is making contact with the tractor frame.

4. 4

   Repair the wire

   [For Code P41] Repair the wire using OEM-approved splicing methods and heat-shrink tubing.

5. 5

   Reconnect and reinstall

   [For Code P41] Reconnect the EMU C105 connector and reinstall the relay.

6. 6

   Test the system

   [For Code P41] Turn the key ON and test the fender PTO switch to ensure the code clears and the PTO engages properly.