Case IH 382 – ENG / ECU: Error detected in cold start relay 2

This code indicates a circuit failure or malfunction associated with the second cold start relay, which is typically part of the engine's intake grid heater system (or glow plug circuit, depending on the specific engine). The system has detected that the relay is either open, shorted, or not responding to the command signal to activate the cold start assist.

• MX Magnum
• STX Steiger
• Magnum Series Tractors (e.g., 235–340 Series 4)
• Steiger Series Tractors
• Maxxum Series Tractors
• Case Construction Equipment (e.g., 580M / 580N / 580SM Series 2 Loader Backhoes)
• Self-Propelled Windrowers (e.g., WDX2302)

1. 1

   Check battery voltage to ensure batteries are fully charged, as low voltage during cranking can sometimes trigger false relay codes.

2. 2

   Visually inspect Cold Start Relay 2 (usually mounted on a bracket near the engine intake manifold or grid heater), checking heavy-gauge cables and smaller control wires for corrosion, fraying, or loose terminal nuts.

3. 3

   Check the main fuses/fusible links supplying power to the grid heater and the smaller fuses protecting the ECU relay control circuits.

4. 4

   Perform a relay bench test by measuring resistance across the relay coil terminals (should not be open or shorted) and applying 12V to check for continuity across the large high-current terminals.

5. 5

   Test the harness and ECU signal by disconnecting the relay, turning the key to the ON position in cold ambient conditions, and using a multimeter to verify the ECU is sending the 12V command signal to the relay.

1. 1

   Disconnect power

   Turn off the ignition and disconnect the negative (-) battery cable(s) to prevent accidental shorts, as the grid heater cables carry very high amperage directly from the battery.

2. 2

   Locate the relay

   Find the cold start relay assembly on the engine block or intake manifold bracket.

3. 3

   Remove wiring

   Carefully remove the retaining nuts holding the heavy-gauge high-current cables to the relay studs. Then, disconnect the smaller control wire harness connector.

4. 4

   Dismount the relay

   Remove the mounting bolts securing the relay to its bracket and remove the old unit.

5. 5

   Install the new relay

   Bolt the new relay into place.

6. 6

   Reconnect wiring

   Reattach the control harness. Reinstall the heavy-gauge cables onto the studs and tighten the nuts securely (do not overtighten, as this can crack the relay housing).

7. 7

   Restore power and clear codes

   Reconnect the negative battery cable. Use a diagnostic scan tool to clear the inactive ENG 382 fault code from the ECU.

8. 8

   Test operation

   Turn the key to the ON position and verify the cold start wait-to-start light illuminates and the relay clicks on without throwing a new code.