New Holland ENG 3702 – Engine Control Unit (ECU): Injection Control: Detection of Failed Engine Start

This fault code indicates that the engine failed to start during cranking. The underlying technical condition is that the engine could not maintain the required starting speed (cranking RPM) or failed to build sufficient fuel rail pressure for the injectors to fire.

• T4
• T5
• T6
• T6000 series
• T7
• T7000 series
• T8
• T9 series
• CR series
• CR8.90
• CR9.90
• CR9090
• CX series
• CX8080
• CX8090 Elevation
• L series
• C series

1. 1

   Verify that the batteries are fully charged and the starter motor is turning the engine over at the minimum required RPM (slow cranking will prevent starting).

2. 2

   Ensure there is adequate fuel in the tank and that it is not contaminated. Check for air intrusion in the low-pressure fuel lines.

3. 3

   Use a diagnostic scan tool to monitor the actual fuel rail pressure during cranking. It must reach the minimum threshold required to command the injectors.

4. 4

   Monitor the engine speed (RPM) signal via the scan tool during cranking to ensure the Engine Speed Sensor (crankshaft/camshaft sensor) is reading accurately and consistently.

5. 5

   Inspect the wiring harnesses and connectors for the fuel rail pressure sensor and the engine speed sensor for corrosion, chafing, or loose pins.

1. 1

   Resolve Cranking Issues

   If the engine is cranking slowly, charge or replace the batteries, clean the battery terminals, and test the starter motor.

2. 2

   Service the Fuel System

   If cranking speed is normal but the engine won't start, replace the primary and secondary fuel filters. Bleed the fuel system completely to ensure no air is trapped in the lines.

3. 3

   Test/Replace the Fuel Rail Pressure Sensor

   If the scan tool shows erratic or zero fuel rail pressure during cranking (and the low-pressure fuel supply is confirmed good), test the fuel rail pressure sensor. Replace it if it is faulty or biased.

4. 4

   Test/Replace the Engine Speed Sensor

   If the scan tool shows no RPM or erratic RPM during cranking, test the engine speed sensor and its wiring circuit. Replace the sensor if it fails resistance or signal tests.

5. 5

   Clear and Verify

   After repairs, use a diagnostic tool to clear the ENG 3702 fault code. Attempt to start the engine to verify the repair.