Case IH 19276 – Engine ECU: Timeout Error of CAN-Receive-Frame AIR1

A CAN communication error indicating the Engine ECU is not receiving the 'AIR1' frame (containing Air Compressor and Service Brake Unit information) within the programmed time limit. This can be caused by a defective CAN controller inside the Service Brake Unit, under-voltage or loss of power to the unit, or a disconnected, broken, or short-circuited CAN bus cable.

• Tier 4b
• T7 Series
• Maxxum
• Optum

1. 1

   Verify that the Service Brake Unit is receiving proper operating voltage, as a dead module cannot broadcast CAN messages.

2. 2

   Visually inspect the wiring harness connecting the Service Brake Unit to the Engine ECU for chafed wires, pinched cables, or melted insulation.

3. 3

   Disconnect the Service Brake Unit and Engine ECU connectors and inspect for water intrusion, corrosion, or pushed-out pins.

4. 4

   With the batteries disconnected, measure the resistance across the CAN High and CAN Low pins to ensure network integrity (should typically read around 60 ohms).

5. 5

   Test the specific CAN lines for open circuits or shorts to ground or power.

1. 1

   Power Down

   Turn off the ignition and disconnect the tractor's battery to prevent electrical spikes.

2. 2

   Locate the Module

   Locate the Service Brake Unit / Air Compressor control module on the tractor.

3. 3

   Inspect and Clean

   Disconnect the main harness to the module. Clean the contacts with electrical contact cleaner and ensure no pins are bent.

4. 4

   Repair Wiring

   If the diagnostic continuity test revealed a broken wire or short circuit in the CAN lines, splice and repair the damaged section of the wiring harness using weather-sealed connectors.

5. 5

   Restore Power

   Reconnect the battery and turn the key to the ON position. Check if the code changes from 'Active' to 'Inactive.'

6. 6

   Replace Module (If Necessary)

   If the wiring, grounds, and power supply to the Service Brake Unit are all perfectly intact, the internal CAN controller of the Service Brake Unit has failed. The unit must be replaced.

7. 7

   Clear Codes

   Use the Case IH Electronic Service Tool (EST) to clear the fault code and test-drive the tractor to ensure the air brake system communicates properly with the engine.