Case IH 3468 – Engine Control Module (ECM / EDC): Water pump actuator reports a general error

The water pump actuator monitors its own health and transmits its status to the engine computer via CAN bus messages. A 'general error' means the actuator's internal controller has detected a failure state such as motor stall, spin-up or spin-down failure, over/under current, over/under voltage, motor not at target speed, or over temperature.

• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Magnum Tractors
• Steiger Tractors

1. 1

   Inspect the Power Supply: Check the wiring and connector at the water pump actuator for loose pins, corrosion, or chafing. Test the power and ground circuits under load to ensure the actuator is receiving steady battery voltage.

2. 2

   Check CAN Bus Communication: Inspect the CAN High and CAN Low lines between the Water Pump Controller and the ECM for short circuits or broken wires.

3. 3

   Mechanical Inspection: With the engine off, check if the water pump impeller or drive mechanism is mechanically stalled, seized, or blocked by debris.

4. 4

   Voltage Check: Verify the machine's alternator is not overcharging or undercharging, as the actuator controller will throw a general error for over/under voltage conditions.

1. 1

   Power Down

   Turn off the engine, remove the key, and disconnect the negative battery cable.

2. 2

   Harness Inspection

   Disconnect the electrical harness at the water pump actuator. Clean the contacts with electrical contact cleaner and verify pin tension.

3. 3

   Circuit Testing

   Reconnect the battery. Turn the key to the ON position (engine off). Use a multimeter to verify proper voltage at the actuator supply pins and verify ~60 ohms of resistance across the CAN bus network pins.

4. 4

   Actuator Replacement

   If the wiring, voltage, and CAN bus integrity are all within specification, the internal controller of the water pump actuator has failed. You must replace the Electrically Controlled Coolant Pump / Actuator assembly.

5. 5

   Reassembly

   Install the new water pump actuator, torque mounting bolts to OEM spec, and reconnect the electrical harness.

6. 6

   Clear and Test

   Reconnect the battery, use a diagnostic tool (like the Case IH EST) to clear the fault codes, and run the engine. Verify that the water pump initializes correctly at startup and reaches target speed without setting the code.