Case IH 3145 – Engine Control Module (ECM) / EDC: Terminal 15 - no signal

The control module is not detecting the expected voltage signal from the ignition switch, or the signal was unexpectedly lost while the machine was operating.

• Magnum 235-340 (Series 4)
• Steiger series
• Puma 165-225 CVX
• Maxxum
• Farmall
• Axial-Flow series
• Case loaders
• Case excavators

1. 1

   Verify overall battery voltage and check all cabin and engine bay fuses related to the ignition circuit and ECM power.

2. 2

   Access the back of the ignition switch and verify that the Terminal 15 pin outputs steady battery voltage when the key is turned to the 'ON' position.

3. 3

   Locate the ignition/power relays in the fuse panel, listen for the relay 'click' when the key is turned, and test for internal shorts or open circuits.

4. 4

   Trace the Terminal 15 circuit wire from the ignition switch/relay to the ECM, checking for open circuits, chafed wires shorting to the chassis (ground), or loose/corroded connector pins.

1. 1

   Disconnect Power

   Always disconnect the negative battery cable before performing electrical repairs to prevent short circuits.

2. 2

   Replace the Ignition Switch

   If the switch failed the continuity/voltage test, remove the retaining nut on the dash panel, pull the switch out from the rear, disconnect the wiring harness, and install the new switch.

3. 3

   Replace the Relay

   If the ignition relay is burnt out or failing to close the circuit, pull it from the fuse block and replace it with a new relay of the exact same amperage rating.

4. 4

   Repair the Wiring Harness

   If a break or short is found in the Terminal 15 wire, cut out the damaged section. Splice in a new section of wire using weather-resistant heat-shrink butt connectors, or replace the damaged terminal pins at the ECM/switch connectors.

5. 5

   Reassemble and Clear Codes

   Reconnect the battery. Turn the key to the 'ON' position to verify power is restored. Connect a diagnostic scan tool to the machine's CAN bus port and clear the inactive 3145 fault code. Start the engine to ensure the code does not return.