John Deere 2798.06 – Engine Control Unit (ECU): Injection Valve Supply Voltage 2, Resistance Too Low

The Engine Control Unit (ECU) has detected a short circuit or abnormally low electrical resistance in the high-voltage supply circuit powering the second bank of electronic fuel injectors. This indicates that electrical current is finding an unintended path to ground, which can damage sensitive electronic components, affect the proper operation of the injection system, and lead to performance issues or engine shutdown.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 204L
• 304L
• 7210R
• 7230R
• 7250R
• 7270R
• 7290R
• 7310R
• 7400A TerrainCut
• 7500A
• 7700A
• 8000A E-Cut Hybrid

1. 1

   Inspect the wiring harness and connectors leading to the Bank 2 injection valve for chafing, melted insulation, wear, or exposed wires making contact with metal engine surfaces.

2. 2

   Disconnect the injector and the ECU harness, then use a digital multimeter to measure circuit resistance and check for continuity to ground on the supply wire.

3. 3

   Measure the internal resistance of the fuel injector solenoid to ensure it has not failed internally and shorted out.

1. 1

   Isolate the Short

   Based on the multimeter readings, locate the exact point of the short to ground.

2. 2

   Repair the Harness

   If the fault is in the wiring or connectors, repair the damaged section of the harness or replace the connector pigtail. Ensure the repaired wiring is routed away from sharp metal edges or high-heat sources.

3. 3

   Replace the Injector

   If the wiring tests fine but the injector itself has an internal short circuit (abnormally low resistance), depressurize the fuel system and replace the affected fuel injector.

4. 4

   Clear and Test

   Reconnect all components. Turn the key to the ON position and use a diagnostic scan tool to clear the ECU 002798.06 fault code. Start the engine and perform a functional test to ensure the fuel injection system is stable and the code does not return.