Case IH 19598 – DCU (Dosing Control Unit): CAN receive frame EEC1 (Driver demand, eng speed, eng torque) | too many CAN messages | P0600 Serial Communication Link

A severe CAN bus communication error where the control module is being flooded with too many messages on the EEC1 frame, triggering a P0600 Serial Communication Link error and causing a breakdown in communication between the engine and the emissions/dosing systems.

• Tier 4a
• Tier 4 Case IH and New Holland equipment
• Magnum 235-340 (Series 4)
• Steiger 350-600
• Farmall series
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230
• T8.xxx Series
• T7 Series

1. 1

   Check for accompanying CAN-related codes (e.g., 19599, 19604, 19606) which indicate a broader CAN network failure rather than an isolated module issue.

2. 2

   With the battery disconnected, measure the resistance across the CAN High and CAN Low pins. A healthy CAN network should read exactly 60 Ohms. If it reads 120 Ohms: A terminating resistor is missing/failed, or the CAN bus wiring is broken. If it reads Open (Infinite): There is a disconnected connector or completely severed wire.

3. 3

   Visually inspect the CAN wiring harness and connectors between the ECM and the DCU for chafing, corrosion, or pin push-out.

1. 1

   Disconnect Power

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

2. 2

   Repair Wiring/Connectors

   If the diagnostic checks revealed an open circuit or damaged wiring between the ECM and DCU, repair the broken wires or replace the damaged harness section.

3. 3

   Replace Terminating Resistor

   If the CAN bus resistance measured 120 Ohms and the wiring is intact, locate and replace the faulty 120-Ohm terminating resistor on the network.

4. 4

   Test/Replace the DCU

   If the wiring is perfect and the resistance is 60 Ohms, the DCU itself is likely internally shorted and flooding the network with messages. Replace the DCU.

5. 5

   Reprogramming

   If the DCU is replaced, the new module will require OEM software installation and configuration (via the Case IH EST diagnostic tool) to sync with the tractor's ECM.

6. 6

   Clear Codes

   Reconnect the battery, clear the fault codes, and run the machine through a standard operating cycle to verify the P0600 communication link error does not return.