Case IH 19579 – DCU (Dosing Control Unit): CAN receive frame E2SCR (Dosing, Exh gas flow, Exh gas temp, Error Suppression, Heater, Long Term failure) _timeout _P0600 Serial Communication Link

A CAN bus communication timeout indicating the control module is failing to receive the 'E2SCR' data frame over the SAE J1939 CAN network, which contains critical operating parameters for the Selective Catalytic Reduction (SCR) emissions system.

• Tier 4a
• Case IH Magnum Series: 235, 260, 290, 315, 340 (Series 4)
• Case IH Steiger / Quadtrac Series: 350, 400, 450, 500, 550, 600
• Case IH Puma Series
• Case IH Axial-Flow Combines: 7230, 8230, 9230

1. 1

   Inspect the CAN bus wiring harness connecting the DCU, the Engine ECU, and the SCR sensors for chafed wires, open circuits, or short circuits.

2. 2

   Disconnect the DCU and ECU connectors to check for pushed-out pins, moisture intrusion, or corrosion, which commonly interrupt serial communication.

3. 3

   Verify that the DCU is receiving proper supply voltage and has a solid ground (voltage spikes above 36.7V can cause the DCU to shut down).

4. 4

   Measure the resistance across the CAN High and CAN Low pins to ensure the network's terminating resistors are intact (a healthy CAN network typically reads 60 ohms).

5. 5

   Connect the CNH Electronic Service Tool (EST) to see if the DCU is online and check for available software updates.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical spikes during repair.

2. 2

   Harness Repair

   If the diagnostic checks reveal damaged wiring on the J1939 CAN network, splice and seal the affected wires using an OEM-approved wiring repair kit, or replace the damaged harness section.

3. 3

   Clean Connections

   Apply dielectric grease to the cleaned connectors of the DCU and reconnect them securely.

4. 4

   DCU Replacement

   If the wiring, power, ground, and CAN resistors test good but the DCU still fails to broadcast or receive the E2SCR frame, the DCU has suffered an internal hardware failure. Remove the mounting hardware, disconnect the DEF lines and electrical connectors, and install the new DCU.

5. 5

   Software Configuration

   If a new DCU is installed, it will require software installation and configuration using the CNH Electronic Service Tool (EST). Note: CNH requires troubleshooting to be documented in their ASSIST system before they will issue the passwords required to flash a new DCU.

6. 6

   Clear Codes and Test

   Reconnect the battery, clear the inactive P0600 / 19579 fault codes, and run the engine to operating temperature to verify that SCR communication has been restored and the code does not return.