Case IH 19338 – Engine Control Unit (ECU) / Engine Control Module (ECM): CAN timeout error related to the GPM12 (General Purpose Message #1/2)

The GPM12 message broadcasts critical engine parameters, specifically the engine speed upper and lower limits and the idle governor set point. A timeout error means that the control module expected to receive or transmit this data packet over the CAN bus but did not see it within the required time window, indicating a communication failure.

• Tier 4b
• Case IH agricultural equipment equipped with Tier 4B (and some Tier 4A) FPT diesel engines
• Puma
• Magnum
• Steiger
• Optum
• combines

1. 1

   Verify the installation and proper connection of the Engine Control Unit (ECU) and the Instrument Cluster to the CAN vehicle network.

2. 2

   Inspect the CAN bus harness for chafed wires, broken lines, or disconnected plugs.

3. 3

   Use a multimeter to check the CAN High and CAN Low lines for proper network resistance (typically 60 ohms across the bus with the battery disconnected) and ensure there are no short circuits to ground or power.

4. 4

   Verify the correct operating conditions and voltage supply to the CAN controller.

1. 1

   Power Down

   Turn off the machine and disconnect the negative battery cable to prevent electrical damage during testing.

2. 2

   Access Modules

   Locate the Engine Control Unit (ECU) and the Instrument Cluster.

3. 3

   Inspect Connectors

   Disconnect the main harness connectors at both the ECU and the Instrument Cluster. Inspect the pins for corrosion, moisture, or pins that have been pushed back into the connector housing. Clean with contact cleaner if necessary.

4. 4

   Test Continuity

   Perform a continuity test on the CAN wiring between the ECU and the Chassis CAN network.

5. 5

   Repair Wiring

   If a break or short circuit is found, repair the damaged section of the wiring harness using appropriate CAN bus repair techniques (e.g., twisted pair splicing) or replace the affected harness section.

6. 6

   Reassemble and Clear Codes

   Reconnect all modules and the battery. Connect the Case IH Electronic Service Tool (EST) to the diagnostic port and clear fault code 19338.

7. 7

   Verify Repair

   Start the engine and monitor the EST to ensure the GPM12 message is broadcasting correctly. If the wiring tests perfectly but the code immediately returns, the internal CAN controller within the ECU or Instrument Cluster is likely defective and the module will require replacement and reprogramming.