Case IH 19580 – DCU (Dosing Control Unit): CAN receive frame E2SCR | too many CAN messages | P0600 Serial Communication Link

The module responsible for the Selective Catalytic Reduction (SCR) emissions system is being overwhelmed by 'too many CAN messages' on the E2SCR data frame, which carries critical data regarding DEF dosing, exhaust gas flow, exhaust temperatures, and heater status, disrupting the serial communication link across the machine's network.

• Tier 4a
• Case IH Magnum Series 235
• Case IH Magnum Series 260
• Case IH Magnum Series 290
• Case IH Magnum Series 315
• Case IH Magnum Series 340
• Case IH Steiger Series (350 to 600 horsepower)

1. 1

   Check for companion CAN timeout codes that often accompany DCU communication failures, such as 3537, 3541, or 3555.

2. 2

   Inspect the CAN bus wiring harness connecting the DCU to the Engine Control Module (ECM) for chafing, shorts to ground, or open circuits.

3. 3

   Inspect the DCU electrical connectors for moisture intrusion, corrosion, or bent pins, which can corrupt the CAN signal.

4. 4

   Verify the DCU is receiving stable voltage and has a clean ground connection, as voltage drops can cause transceiver malfunction.

1. 1

   Power Down

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

2. 2

   Locate the DCU

   Locate the Dosing Control Unit, which is typically mounted near the DEF/AdBlue tank and the DEF supply module.

3. 3

   Harness Repair

   If the diagnostic checks revealed damaged wiring or corroded pins on the CAN backbone, repair the wiring harness or replace the connector pigtail. Clean any light corrosion with electrical contact cleaner and apply dielectric grease.

4. 4

   Clear Codes

   Reconnect the battery, power on the machine, and use the CNH Electronic Service Tool (EST) to clear the fault codes. Run the machine to see if code 19580 returns.

5. 5

   Replace the DCU

   If the wiring is 100% intact, the CAN bus resistance measures correctly (typically 60 ohms across the network), and the code persists, the DCU's internal communication circuitry has failed. Remove the mounting hardware and disconnect the DEF lines and electrical connectors to remove the DCU.

6. 6

   Software Configuration

   Install the new DCU. Note: A new DCU requires OEM software installation. You must use the CNH EST to program the module to the tractor. CNH requires troubleshooting to be performed and documented via 'Assist' before they will issue the necessary software passwords to unlock and flash the new module.