Case IH 518049-19 - ACM – ACM: Differential lock keypad disconnected

This code indicates that the control module has lost communication with the differential lock keypad/switch assembly, or it has detected an open circuit/physical disconnection in the keypad's wiring harness.

• MAGNUM AFS Connect
• Magnum AFS Connect series
• Steiger AFS Connect series
• Puma AFS Connect series

1. 1

   Check for Related Codes: Use the Electronic Service Tool (EST) to scan for other DTCs. Multiple '-19' codes may indicate the entire armrest is losing power or CAN-BUS communication.

2. 2

   Visual Inspection: Inspect the armrest for signs of physical damage, liquid spills, or debris that could have shorted or disconnected the keypad.

3. 3

   Harness Verification: Check the internal armrest wiring harness for pinched, broken, or rubbed-through wires leading to the differential lock keypad.

4. 4

   Connector Check: Verify that the multi-pin connector at the back of the differential lock keypad is fully seated and locked into place.

5. 5

   Voltage/Ground Test: Verify that the keypad is receiving proper operating voltage and ground from the ACM.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical shorts during disassembly.

2. 2

   Disassemble the Armrest

   Carefully remove the armrest cover panels to access the internal control modules and switch clusters.

3. 3

   Inspect and Reconnect

   Locate the differential lock keypad. Disconnect its wiring harness, inspect the pins for corrosion or pushed-out terminals, and firmly reconnect it.

4. 4

   Harness Repair

   If the wiring harness is damaged (e.g., pinched by the armrest pivot mechanism), repair the broken wires or replace the internal armrest harness.

5. 5

   Replace the Keypad

   If the wiring and connections are good but the code persists (indicating an internal failure of the keypad's circuit board), remove the retaining screws/clips and replace the differential lock keypad assembly.

6. 6

   Reassemble and Clear Codes

   Reassemble the armrest, reconnect the battery, and connect the EST to the vehicle. Clear the inactive DTCs and test the differential lock engagement to verify the repair.