AGCO POWER EEM4 ECU Coolant Temperature Sensor: Temperature HIGH, ALARM

This guide provides instructions on how to resolve the “Temperature HIGH, ALARM” issue for the AGCO POWER EEM4 ECU coolant temperature sensor, applicable to JCB Stage V Tier 4 engines.

Description

The alarm indicates that the measured coolant temperature has exceeded the overheating alarm limit.

Related Contents:

2024 JCB ServiceMaster 4 v24.3.1 Free Download for Win 10 Win11

JCB Electronic Service tool

Possible Causes

• Fan belt slipping or broken: Check for wear, tension, and integrity.
• Incomplete cooling system fill: Ensure the cooling system is fully filled with the appropriate coolant mixture.
• Defective water pump: Inspect for proper operation and flow.
• Clogged cooling system: Check for blockages in hoses, radiator, and other components.
• Defective or removed thermostat: Verify the thermostat is present, functional, and properly oriented.
• Upside-down thermostat: Ensure the thermostat is installed correctly.
• Non-pressure-tight radiator filler cap: Check the cap for proper sealing and pressure retention.
• Engine overload: Assess the engine load to ensure it is not being overworked.
• Defective coolant temperature sensor wiring: Inspect wiring for damage, disconnections, or corrosion.
• Defective coolant temperature sensor: Test and replace if necessary.

ECU Reaction

When the alarm is triggered:

• The fault code (FC) is stored.
• The warning lamp is activated.
• The engine will shut down after 30 seconds.
• A CAN message will indicate an impending shutdown.

Solution Steps

1. Save the Error Log: Document the fault codes and any related data for future reference.
2. Examine the Fan Belt and Tension:
   • Check for wear and proper tension.
   • Replace if damaged or worn.
3. Examine the Coolant Level:
   • Ensure the system is fully filled.
   • Top up with the appropriate coolant if necessary.
4. Examine the Condition of the Radiator:
   • Inspect for blockages or damage.
   • Clean or repair as needed.
5. Examine the Mechanical Condition of the Engine:
   • Check for any mechanical issues that may cause overheating.
6. Examine the Coolant Temperature Sensor Wiring:
   • Inspect wiring, connectors, and contact surfaces for damage or oxidation.
   • Clean or repair as necessary.
7. Test the Coolant Temperature Sensor:
   • Replace with a known good sensor to determine if the original is defective.

For additional repair cases for JCB, refer to: JCB Trouble Repair