Case IH 3047 – Engine Control Module (ECM) / Electronic Diesel Control (EDC): High pressure pump relay - short circuit to battery

The control circuit for the high-pressure fuel pump relay is receiving unintended battery voltage. A short to power can cause the relay to remain energized continuously or disrupt the electronic fuel delivery system, potentially causing engine running issues or preventing the engine from shutting down properly.

• Puma 140
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225 CVX
• Steiger Series
• Magnum Series
• MX Series
• TG Series

1. 1

   Visually inspect the wiring harness between the ECM and the high-pressure pump relay for chafed insulation, melted wires, or pinched harnesses that could bridge the relay control wire to a 12V power source.

2. 2

   Remove the high-pressure pump relay and test it with a multimeter for internal shorts across the coil pins.

3. 3

   Verify the battery voltage to the ECM to ensure voltage is not too high or too low.

4. 4

   Ensure there are no secondary mechanical issues such as fuel inlet/return restriction, air ingress, or abnormal fuel supply pressure to the high-pressure pump.

1. 1

   Disconnect the battery

   Disconnect the machine's battery to prevent further electrical damage during testing and repair.

2. 2

   Locate the relay

   Locate the high-pressure pump relay (often designated as the "Main Relay" for the engine fuel system in the fuse/relay panel).

3. 3

   Replace the relay

   If the relay failed the multimeter test (internal short), replace it with a new OEM relay.

4. 4

   Trace and repair the circuit wire

   If the relay is functioning normally, trace the specific circuit wire from the relay block back to the ECM. Repair or splice any sections of the wire that are shorting to battery voltage.

5. 5

   Reconnect the battery

   Reconnect the battery.

6. 6

   Clear the fault code

   Turn the ignition key to the ON position and use a diagnostic service tool to clear fault code 3047 from the ECM memory.

7. 7

   Test the system

   Start the engine and monitor the system to ensure the code does not return and the high-pressure fuel pump operates correctly.