Case IH 19143 – Engine Control Module (ECM) or Aftertreatment / Dosing Control Unit (DCU): DLC Error of CAN-Receive-Frame CRI1, Catalyst DEF/AdBlue Information Frame

A Controller Area Network (CAN) communication error where the ECM or DCU receives a CRI1 frame with an incorrect data length. This indicates the data packet sent by the DEF Quality Sensor or DEF Supply Module is corrupted, incomplete, or unreadable, typically caused by a failing DEF Quality Sensor circuit board, corroded wiring, or a CAN bus communication glitch.

• Tier 4b
• Case IH Tier 4B
• Case IH Tier 4 Final
• Steiger
• Quadtrac
• Quadtrac 500
• Quadtrac 580
• Magnum
• Puma
• Optum
• 240 Series Combines
• 7240 Combine
• 8240 Combine
• 9240 Combine
• 7130 Series Combine
• Case Construction wheel loaders
• 621F
• 621G
• 721F

1. 1

   Check battery and system voltage, as low battery voltage is a leading cause of phantom CAN bus and sensor codes.

2. 2

   Visually inspect the DEF Quality Sensor, which is typically integrated into the DEF tank header/sending unit on top of the DEF tank.

3. 3

   Inspect the 4-cavity electrical connector (C181M) at the DEF Quality Sensor for green corrosion, moisture, or backed-out pins caused by ammonia gas venting.

4. 4

   Perform a CAN bus continuity test using a multimeter on the CAN High and CAN Low wires between the DEF Quality Sensor harness and the ECM.

5. 5

   Check for accompanying codes like 19144, 19141, or 19142, which further isolate the failure to the sensor itself.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical spikes on the CAN bus during repair.

2. 2

   Clean/Repair Wiring

   If corrosion is found at the DEF Quality Sensor connector, clean the terminals with electronic contact cleaner. If the connector is heavily damaged, splice in a new pigtail connector.

3. 3

   Replace the DEF Quality Sensor / Header

   If the wiring tests good but the DLC error persists, the internal circuit board of the DEF Quality Sensor has likely failed. Disconnect the electrical harness and DEF fluid lines from the DEF header. Unbolt the DEF header/sensor assembly from the top of the DEF tank. Install the new DEF Quality Sensor assembly, ensuring the tank O-ring/gasket is seated properly to prevent future leaks. Reconnect the fluid lines and electrical connector.

4. 4

   Clear Codes and Test

   Reconnect the battery. Connect a diagnostic scan tool (such as the CNH Electronic Service Tool) to clear the 19143 fault code. Run the engine and perform an SCR system test or stationary regeneration to verify the CAN communication is restored and the code does not return.