Case IH 3154 (DTC 6A14) - ECU – Engine Control Unit (ECU A-095): Intake air heater actuator is shorted to battery voltage

The control module has detected a short-to-high source condition (battery voltage) in the control circuit for the intake air heater relay (designated as relay K-023 in Case IH schematics).

• MAXXUM T4E
• 240 Series Axial-Flow Combines (5130, 7240, 8240, 9240)
• Puma Series (Puma 125, 210)
• Magnum Series (MX210, MX230, MX255, MX285)
• Farmall Series (40, 45, 50)

1. 1

   Verify if an external power supply is connected improperly or if the charging system is faulty and causing an overvoltage condition

2. 2

   Inspect the relevant wiring harnesses and connectors between the ECU (A-095) and the intake air heater relay (K-023) for damaged wires, bent or dislocated pins, and corroded terminals

3. 3

   Flex the wiring harnesses involved to reveal any intermittent breaks or shorts to power in the wiring

4. 4

   Test the intake air heater relay (K-023) and its solenoid to see if it has failed internally and is shorting the circuit to battery voltage

1. 1

   Locate Components

   Use your machine's specific service manual to locate the Engine Control Unit (ECU A-095) and the Intake Air Heater / Grid Heater Relay (K-023).

2. 2

   Disconnect and Isolate

   Turn off the machine and disconnect the wiring harness connectors at both the ECU and the K-023 relay.

3. 3

   Test the Circuit

   Using a multimeter, test the K-023 control circuit conductor for continuity to a high source (battery voltage).

4. 4

   Repair Wiring

   If continuity to battery voltage is found while both ends are disconnected, the wiring harness is shorted. Locate the shorted section of the conductor and repair or replace the harness.

5. 5

   Test/Replace the Relay

   If the wiring harness tests good, the short is likely internal to the intake air heater relay (K-023). Replace the relay.

6. 6

   Reassemble and Verify

   Reconnect all harnesses, ensuring connectors are fully seated. Clear the fault codes and cycle the key/engine to verify the repair.

7. 7

   ECU Flash

   If the wiring and relay are both in perfect condition and the code persists, OEM manuals suggest checking the ECU A-095 for the appropriate software and re-flashing it if necessary.