Case IH 11 – Instrument Cluster (ICU), Body Control Module (BCM), or PTO/Transmission Controller: Open circuit through PTO indicator lamp, check lamp circuit

The fault indicates an "open circuit" in the Power Take-Off (PTO) indicator lamp circuit. This means the control module is attempting to send a signal (or monitor the ground path) to illuminate the PTO indicator lamp on the dash, but it is detecting infinite resistance or a break in the electrical path.

• MX Maxxum
• MX Series (MX80C, MX90C, MX100, MX110, MX120, MX135)
• MXM Series (MXM120, MXM130, MXM140, MXM155, MXM175, MXM190)
• Puma Series (165, 180, 195, 210, 225, and CVX models)
• Compact Tractors (D40, DX40, D45, DX45)

1. 1

   Read and record all stored DTCs and freeze-frame data using a diagnostic scan tool.

2. 2

   Perform a visual inspection of the PTO switch, the instrument cluster harness, and connectors for obvious damage, corrosion, pushed-back pins, or rodent damage.

3. 3

   Verify that all fuses and relays related to the PTO power/ground and instrument cluster are intact.

4. 4

   Turn the key to the OFF position and measure the voltage/resistance at the wiring harness for the indicator lamp circuit. Check for continuity between the lamp socket and the control unit; an open switch or blown bulb will show infinite resistance.

5. 5

   Check for proper ground and battery voltage at the PTO switch harness.

1. 1

   Disconnect the tractor's battery

   Disconnect the tractor's battery to prevent electrical shorts during repair.

2. 2

   Access the instrument cluster

   Access the instrument cluster or the specific dash panel where the PTO indicator lamp is housed.

3. 3

   Remove the PTO indicator lamp/bulb

   Remove the PTO indicator lamp/bulb from its socket.

4. 4

   Test the bulb for continuity

   Test the bulb for continuity using a multimeter. If the bulb is blown (open circuit), replace it with a new OEM bulb/indicator.

5. 5

   Trace the wiring harness

   If the bulb tests good, use a multimeter to trace the wiring harness from the lamp socket back to the PTO switch and the control module.

6. 6

   Repair broken wires or replace pins

   Repair any broken wires or replace corroded connector pins that are causing the open circuit.

7. 7

   Reinstall the indicator lamp

   Reinstall the indicator lamp and reassemble the dash/instrument cluster panels.

8. 8

   Reconnect the battery

   Reconnect the battery.

9. 9

   Verify repair

   Start the tractor and safely engage the PTO switch to verify that the indicator lamp illuminates and the fault code clears.