Case IH 18437: ICP2XCM_Slow_MR CAN message rolling counter failure

A 'rolling counter failure' on a CAN bus indicates a communication error or data loss between control modules. The receiving module detects that the counter value in the 'ICP2XCM_Slow_MR' message is missing, repeated, or out of sequence, pointing to a dropped communication signal, a CAN bus wiring issue, or an internal module fault.

• MAXXUM T4E

1. 1

   Verify that the applicable control modules have proper voltage and a solid ground circuit.

2. 2

   Disconnect the connectors of the modules communicating on this specific CAN bus and inspect for corrosion, backed-out pins, or moisture.

3. 3

   Test the CAN communication circuit wiring for opens, shorts to ground, or shorts to power.

4. 4

   Perform a full system scan to see if other modules are also reporting 'Lost Communication' errors to help isolate where the break in the CAN bus is located.

1. 1

   Clear and Verify

   Clear the DTCs and cycle the ignition to see if the rolling counter failure returns immediately (hard fault) or intermittently.

2. 2

   Repair Wiring

   If the diagnostic checks reveal high resistance or a break in the CAN bus wiring harness, repair the affected wires or replace the damaged harness section.

3. 3

   Clean Connections

   If corrosion is found at the module connectors, clean the pins and apply dielectric grease, then reconnect and retest.

4. 4

   Module Substitution/Replacement

   If the wiring, power, and ground circuits all test perfectly, the fault is likely an internal hardware failure in the module transmitting the 'ICP2XCM_Slow_MR' message. The module must be substituted with a known good unit or replaced entirely.