Case IH 3157 – Engine Control Module (ECM): ECM Not Detected on CAN bus

The Engine Control Module (ECM) failed to communicate its dataset registration information over the machine's Controller Area Network (CAN bus) within the expected timeframe.

• Farmall
• skid steer
• Steiger T4B
• Magnum 235 - 340 (Series 4)
• Puma 165, 180, 195, 210, 225 CVX
• Maxxum Series
• CE Loader Backhoes (580N, 580SN, 580ST, 590SN, 590ST)

1. 1

   Verify Symptoms: Confirm the presence of the amber warning light and check for any secondary codes that might indicate a specific sensor short.

2. 2

   Inspect CAN bus Wiring: Thoroughly inspect the CAN bus wiring harness leading to the ECM for chafing, breaks, or corrosion.

3. 3

   Check Connectors: Disconnect and inspect the pins on the ECM connectors for damage, moisture, or poor terminal tension.

4. 4

   Verify Power and Ground: Ensure the ECM is receiving proper voltage and has a solid ground connection. A lack of power will prevent the ECM from broadcasting on the CAN bus.

5. 5

   Sensor Inspection: Check for damaged engine sensors that could be shorting out the ECM's internal power supply, causing it to drop off the network.

1. 1

   Disconnect Battery

   Always disconnect the machine's battery before servicing the ECM or main wiring harnesses.

2. 2

   Repair Wiring

   If the diagnostic checks reveal damaged CAN bus wiring or faulty connectors, repair or replace the affected harness sections.

3. 3

   Replace/Reprogram ECM

   If the wiring, power, and ground circuits are fully intact and the ECM still does not communicate, the ECM itself is likely malfunctioning and must be replaced.

4. 4

   Dataset Registration

   If a new ECM is installed, or if the software was recently updated, the engine dataset must be registered to the machine using the CNH Electronic Service Tool (EST).

5. 5

   Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic scan tool to clear the stored 3157 fault code. Run the engine to verify the code does not return.