Case IH 19270 – SCR Control Module / Engine Control Unit (ECU): CAN timeout error - CRI1 message

The fault is triggered when the ECU experiences a timeout waiting for the CRI1 CAN frame. This means the CAN bus is overloaded, the signal is disturbed, or the frame could simply not be received due to a physical wiring defect or a failed DEF sensor module.

• Tier 4b
• Magnum
• Steiger
• Puma
• Maxxum
• Optum
• Farmall
• Axial-Flow 7240
• Axial-Flow 8240
• Axial-Flow 7150
• Axial-Flow 8250
• SV340B
• TR340

1. 1

   Inspect the CAN bus wiring harness between the DEF Head Unit (Catalyst Reagent Sensor) and the Engine Control Unit / SCR Controller

2. 2

   Disconnect the DEF sensor harness and inspect connectors for damaged wires, pushed-out pins, corrosion, or water ingress

3. 3

   Test CAN bus integrity for a short circuit or physical defect that could cause error frames and high bus load

4. 4

   Verify the DEF sensor unit is receiving proper operating voltage and ground

1. 1

   Disconnect Power

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

2. 2

   Repair Wiring

   If the diagnostic checks reveal chafed wires, shorts, or corroded connector pins on the chassis harness leading to the DEF tank, repair or replace the affected pigtail/harness.

3. 3

   Replace the DEF Head Unit

   If the CAN network is intact and communicating properly with all other modules, the internal CAN controller inside the DEF sensor assembly has failed.

4. 4

   Remove the Old Sensor

   Clean the area around the top of the DEF tank to prevent dirt from falling in. Disconnect the electrical connector and the DEF fluid lines. Unbolt/unscrew the DEF head unit from the tank.

5. 5

   Install the New Sensor

   Insert the new combined DEF Level/Temperature/Quality sensor into the tank. Ensure the mounting seal/O-ring is properly seated to prevent leaks. Reconnect the fluid lines and electrical harness.

6. 6

   Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic tool (like the Case IH EST) to clear the 19270 fault code. Verify that the CRI1 message is now actively broadcasting DEF temperature and quality data to the ECU.