Case IH 698 – Engine Control Module (ECM): Engine Controller internal temperature too low

The Engine Control Module (ECM) detects a low signal voltage, an open circuit, or a short to ground on its internal temperature sensor circuit, indicating a hardware anomaly inside the controller.

• MX Magnum
• STX Steiger
• TG Series
• Puma Series
• Puma 125
• Puma 140
• Steiger Series
• Combines
• AFX8010

1. 1

   Inspect the main wiring harness connectors at the ECM for moisture, water intrusion, or corrosion, which can cause internal shorting

2. 2

   Verify the ECM is receiving proper battery voltage and has clean, secure ground connections

3. 3

   Connect a diagnostic service tool to determine if the code is Active or Inactive to rule out a temporary voltage glitch

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the machine's battery negative terminal.

2. 2

   Clean and Inspect

   Disconnect the ECM harness connectors. Thoroughly clean the pins with electrical contact cleaner and ensure no pins are pushed back or damaged.

3. 3

   Re-test

   Reconnect the ECM, restore battery power, and use a diagnostic tool to clear the fault codes.

4. 4

   Run Cycle

   Start the engine and allow it to reach operating temperature to see if code 698 returns.

5. 5

   Replace ECM

   If the code returns and remains Active, the internal temperature sensor has permanently failed. Replace the entire Engine Control Module (ECM).

6. 6

   Flash Calibration

   The new ECM must be flashed/programmed with the correct engine calibration software for your specific Case IH machine using the Electronic Service Tool (EST).