Case IH 3164 (DTC 1A33) - ECU – Engine Control Unit (ECU): Fan speed above maximum threshold

The Electronic Control Unit (ECU) monitors the fan speed sensor (designated as component Z-008) by measuring the time interval between electrical pulses. If the ECU determines that the fan speed is exceeding the maximum allowed threshold for the current engine speed, it triggers this fault.

• MAXXUM T4E
• Magnum Series 4 (235 through 380)
• Puma series (125, 240 CVX)
• Steiger series
• Farmall CVT models (40, 45, 50)
• Axial-Flow Combines (240 series, 7120, 7230, 8010, 9240)

1. 1

   Verify Active Status: Use the in-cab display or the Electronic Service Tool (EST) to confirm if the fault is currently active.

2. 2

   Check Power Supply: Ensure that no external power supply (such as a jump box or external charger) is connected to the tractor. If one is connected, disconnect it and test the system for normal operation.

3. 3

   Check System Voltage: Start the engine and run it at 2000 RPM. Check the battery voltage on the instrument cluster to ensure the alternator is not overcharging the system.

4. 4

   Visual Inspection: Inspect the cooling fan to ensure it is not physically damaged, blocked, or operating erratically.

1. 1

   Start the engine and leave it running.

   Ensure the engine is running to perform the fan clutch diagnostic test.

2. 2

   Locate and unplug the fan clutch electrical connector.

   Identify connector X-811 in the wiring schematic and disconnect it.

3. 3

   Observe the fan's behavior.

   With the connector unplugged, the fan clutch should default to full lock-up (maximum speed).

4. 4

   Replace the Vistronic fan clutch if it does NOT lock up.

   If the fan does not lock up, the Vistronic fan clutch (solenoid Z-008) has suffered an internal mechanical or electrical failure and must be replaced.

5. 5

   Inspect the wiring harness if the fan DOES lock up.

   Leave the connector disconnected. The clutch is functioning mechanically. Inspect the wiring harness between the fan speed sensor (Z-008) and the ECU (A-095) for chafing, shorts, or damaged pins.

6. 6

   Replace the fan speed sensor.

   If the wiring tests good, replace the fan speed sensor.

7. 7

   Clear the fault codes and test run the machine.

   Use the EST to clear codes. Note: If the issue persists after sensor replacement and wiring checks, the ECU A-095 software may need an update or the module itself may be faulty.