Case IH 19581 – DCU (Dosing Control Unit): CAN receive frame E2SCR (Dosing, Exh gas flow, Exh gas temp, Error Suppression, Heater, Long Term failure) _SAE J1939 Check for CAN receive signal _P0600 Serial Communication Link

The control module is failing to receive the E2SCR data frame over the SAE J1939 CAN (Controller Area Network) bus, which contains critical emissions parameters, indicating a general Serial Communication Link failure (P0600).

• Tier 4a
• Case IH Magnum Series: 235, 260, 290, 315, 340 (Series 4)
• Case IH Steiger Series: 350, 400, 450, 500, 550, 600
• Case IH Puma Series

1. 1

   Check for Accompanying Codes: Look for other CAN timeout codes (e.g., 19578, 19579, 19580, 19595). If multiple modules report P0600, the entire J1939 CAN bus may be down. If 19581 is isolated, the issue is specific to the DCU node.

2. 2

   Verify Power and Ground: Check the battery voltage supply and ground circuits to the DCU. A module with low voltage will drop off the CAN network.

3. 3

   CAN Bus Resistance Test: Disconnect the batteries and measure the resistance across the CAN High and CAN Low pins at the diagnostic connector. It should read approximately 60 ohms.

4. 4

   Harness Inspection: Inspect the wiring harness between the Engine Control Unit (ECU) and the DCU for chafing, rodent damage, or melted insulation near the exhaust.

5. 5

   Connector Inspection: Disconnect the DCU harness and check for pushed-out pins, corrosion, or moisture intrusion (DEF fluid migration into the wiring can cause communication shorts).

1. 1

   Disconnect Power

   Turn off the battery disconnect switch to protect the network modules before beginning any physical repairs.

2. 2

   Clean and Reseat Connectors

   If corrosion or moisture is found at the DCU connector, clean the pins with electronic contact cleaner, apply dielectric grease, and reseat the connector securely.

3. 3

   Repair Wiring

   If continuity tests reveal an open circuit or a short to ground on the CAN High or CAN Low wires leading to the DCU, splice and repair the damaged section of the J1939 twisted-pair wiring using OEM-approved heat-shrink connectors.

4. 4

   Replace Terminating Resistors

   If the CAN bus resistance test failed (e.g., reading 120 ohms instead of 60 ohms), locate and replace the failed CAN terminating resistor on that segment of the harness.

5. 5

   Replace the DCU

   If the wiring harness, terminating resistors, power, and ground all test perfectly, the internal CAN transceiver in the Dosing Control Unit has likely failed. Replace the DCU.

6. 6

   Clear Codes

   Reconnect battery power, connect the CNH Electronic Service Tool (EST), clear the fault codes, and run the engine to verify that the E2SCR CAN frame is actively communicating.