Case IH 19303 – Engine Control Module (ECM): Timeout Error of CAN-Transmit-Frame EAC

The Engine Control Module (ECM) has lost communication with the Engine Auxiliary Coolant (EAC) pump/module over the Controller Area Network (CAN) bus. The ECM expects to receive a regular status message (frame) from the EAC node, and this code is logged when that expected signal times out.

• Tier 4b
• Puma
• Magnum
• Optum

1. 1

   Download a Product Status Report using an electronic service tool (e.g., CNH EST) before clearing diagnostic trouble codes.

2. 2

   Inspect the CAN bus wiring harness running between the Engine ECM and the Engine Auxiliary Coolant pump for chafing, breaks, or shorts.

3. 3

   Inspect the electrical connectors at both the EAC pump and the ECM for corrosion, moisture ingress, or bent pins.

4. 4

   Verify the Auxiliary Coolant Pump is receiving proper operating voltage and has a solid ground connection (loss of power causes the CAN node to go offline).

5. 5

   Verify that the aftercooler/auxiliary coolant lines are not blocked or leaking.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent electrical spikes during the repair.

2. 2

   Clean and Reseat Connectors

   Disconnect the harness at the Engine Auxiliary Coolant pump. Clean the contacts with electrical contact cleaner, apply dielectric grease, and firmly reseat the connector.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a broken CAN wire or a damaged power/ground wire, splice and seal the damaged section of the harness.

4. 4

   Replace the EAC Pump

   If the wiring, power, and ground are all intact, the internal CAN transceiver inside the electric Auxiliary Coolant Pump has likely failed. Drain the auxiliary coolant circuit, remove the pump from its mounting bracket, install the new pump, and reconnect the coolant lines and electrical harness.

5. 5

   Refill and Bleed

   Refill the auxiliary coolant circuit to the specified level and bleed any air from the system.

6. 6

   Clear Codes

   Reconnect the battery, connect the electronic service tool, and clear the 19303 fault code from the ECM. Run the engine to verify the code does not return.