Case IH 3702 – Engine Control Unit (ECU) / EDC (Electronic Diesel Control): Injection control: Detection of failed engine start.

The engine failed to start because it could not maintain the required starting speed or failed to build sufficient fuel rail pressure. The Engine Control Unit (ECU) detected that the minimum rail pressure value necessary to allow fuel injection was not reached during cranking.

• skid steer
• Puma
• Magnum
• Steiger
• Farmall
• SR220
• SR250
• SV250
• SV300
• TR270
• TR320
• TV380
• 621G
• 721G
• Axial-Flow 7010
• Axial-Flow 7120
• Axial-Flow 8010
• Axial-Flow 9010

1. 1

   Visual Inspection: Check all high-pressure and low-pressure fuel lines for visible leaks.

2. 2

   Wiring & Harness Check: Inspect the engine harness, connectors, and pins (especially at the ECU and fuel rail pressure sensor) for broken connectors, corrosion, bent pins, or wire breaks.

3. 3

   EST Monitoring: Connect the Electronic Service Tool (EST) and monitor engine cranking speed and actual vs. desired fuel rail pressure.

4. 4

   Fuel System Tests: Check the low-pressure fuel supply (filters, lift pump) for restrictions or air intrusion. If the low-pressure side is good, perform an injector leak-off (return flow) test to see if a faulty injector is bypassing fuel and preventing the rail from building pressure.

1. 1

   Address Leaks

   If the fuel lines have leaks, repair or replace the lines as required. Bleed the fuel system and attempt to start the engine to confirm the fault is eliminated.

2. 2

   Repair Wiring

   If harness damage or bent pins are found at the fuel rail pressure sensor or ECU, repair or replace the connections/wiring.

3. 3

   Replace Faulty Fuel Components

   Based on your diagnostic tests (EST data and leak-off tests), replace the component preventing rail pressure buildup. This is typically a clogged fuel filter, a leaking fuel injector, a failed high-pressure fuel pump, or a faulty fuel rail pressure sensor.

4. 4

   ECU Re-initialization

   If all mechanical and electrical checks pass and the ECU is suspected to be faulty, use the EST service tool to re-initialize the ECU and load the appropriate data-set (requires an authorization code from CNH TSS). If the fault code does not clear after re-initialization, the ECU must be replaced.

5. 5

   Clear Codes

   Clear the fault code using the EST and crank the engine to verify the repair.