New Holland ENG 3259 – Engine Control Unit (ECU): Starter Relay: High Side Power - Short Circuit to Ground

The Engine Control Unit (ECU) controls the starter motor relay using both a low-side and a high-side driver circuit. This fault code is triggered when the ECU detects a short circuit to ground on the high-side driver circuit of the starter relay. This typically prevents the starter from engaging, resulting in a "no-crank/no-start" condition.

• L218
• L220
• L223
• L225
• L230
• SR175
• SV185
• SV250
• SV300
• C227
• C232
• C238
• TR270
• TR340B
• B90B
• B100B
• B115B
• WorkMaster 50
• TD5010-TD5050 series
• Boomer models

1. 1

   Battery Disconnect: Always disconnect and isolate the battery negative lead before carrying out electrical service operations.

2. 2

   Visual Inspection of Relay Base: Locate the starter relay (often designated as K-9104) in the fuse/relay box. Inspect the relay base for backed-out terminals, corrosion, or melted plastic.

3. 3

   ECU Harness Inspection: Inspect the wiring harness connector at the ECU (often designated as A-9000). Look for terminal back-out, moisture, or disconnection.

4. 4

   Wiring Continuity & Short Test: Using a multimeter, test the high-side driver wire running between the ECU and the starter relay base. Check for continuity to ground (which would confirm the short circuit). Look for chafed wire insulation rubbing against the machine's metal frame.

5. 5

   Relay Coil Resistance: Measure the resistance of the starter relay coil with a multimeter to verify if the relay itself has failed internally (a standard 12V relay coil should typically read around 70-220 ohms depending on the exact spec).

1. 1

   Isolate Power

   Turn off the ignition and disconnect the negative battery cable.

2. 2

   Access the Relay

   Open the power distribution box and remove the starter relay.

3. 3

   Repair the Short

   If the diagnostic tests revealed a short to ground in the wiring harness between the ECU and the relay, repair the damaged section of the wire (splice and heat-shrink) or replace the affected harness section.

4. 4

   Replace the Relay

   If the wiring is intact but the relay is internally shorted, install a new OEM starter relay into the socket. Ensure it is seated firmly and no pins are pushed out the back of the connector block.

5. 5

   Restore Power

   Reconnect the negative battery cable.

6. 6

   Clear Codes

   Turn the key to the ON position. Use a diagnostic service tool or the machine's InfoView monitor to clear the ENG 3259 fault code.

7. 7

   Test Operation

   Attempt to start the engine to verify the starter engages properly and the code does not return.