Case IH 3172 – Engine Electronic Control Unit (ECU A-095): Engine coolant temperature has exceeded the pre-warning threshold

The engine coolant temperature has surpassed the pre-warning limit of 106.0 °C (222.7 °F).

• Steiger T4B
• 240 Series Axial-Flow Combines
• 7240
• 8240
• 9240
• Axial-Flow 5130
• 6140
• 7140
• 8120
• 9010
• Puma Series
• Magnum Series
• MX210
• MX230
• MX255
• MX285
• Farmall Pro EP series
• Patriot series
• 4440

1. 1

   Verify if the fault is currently active; if it is active, diagnose the physical cooling system first.

2. 2

   Visually inspect the engine cooling system for obvious over-temperature conditions, leakage, physical damage, or blockages (such as chaff or dirt restricting airflow through the radiator fins).

3. 3

   Determine if the engine simply overheated due to heavy, intensive use or exceptionally high ambient temperatures.

4. 4

   If the engine is not physically overheating but the code is active, check the Coolant Temperature Sensor (B-016) and its wiring harness for an internal short or a signal circuit wire shorted to ground (ECU triggers fault if analog input is less than 0.188 V).

1. 1

   Safe Shutdown & Emergency Move

   If the machine experiences a power loss, command the engine to low idle to enable 30 seconds of operation without power loss to safely move the machine out of the field or traffic.

2. 2

   Cool Down

   Allow the engine to cool down completely before opening the cooling system or performing repairs.

3. 3

   Clear Blockages

   Blow out the radiator, coolers, and rotary screen with compressed air to ensure optimal airflow.

4. 4

   Repair Leaks

   If coolant levels are low due to a leak, repair the damaged hose, water pump, or radiator core, and refill the system with the correct OEM-specified coolant.

5. 5

   Replace Sensor

   If diagnostic checks point to a failed sensor (e.g., internal short), locate sensor B-016 on the engine block/thermostat housing, disconnect the wiring harness, unthread the old sensor, install the new sensor, and reconnect the harness.

6. 6

   Clear Codes

   Turn the key on and use the diagnostic display or a service tool to clear the inactive fault codes and verify normal operation.