New Holland ENG 3716 – ENGINE ECU: Lambda Sensor: O2 Value Above the Max Threshold

The engine control system has detected that the oxygen (O2) concentration measured by the Lambda sensor in the exhaust stream is implausibly high or exceeds the maximum programmed threshold, indicating an excessively lean condition.

• T4 PowerStar (Boomer)
• T5
• T5.95
• T6
• T7
• T8
• T9
• CR9090
• CX8080 Elevation
• CX8090 Elevation
• TC5.70
• TC5.90
• W50C
• W60C
• W70C
• W80C
• B115 C Loader Backhoe
• L series skid steers
• C series skid steers

1. 1

   Inspect the Lambda sensor wiring harness and connector for damage, corrosion, or loose pins, checking for open or short circuits.

2. 2

   Inspect the exhaust system (upstream of the sensor) and the intake manifold for physical leaks that could draw in outside air.

3. 3

   Check the Lambda sensor tip for heavy soot fouling or contamination by coolant or oil.

4. 4

   Use a diagnostic tool (CNH EST or Jaltest) to monitor live Lambda sensor voltage and O2 percentage to verify if the value is pegged at the maximum threshold.

1. 1

   Preparation

   Ensure the engine is turned off and the exhaust system/DPF assembly has completely cooled down to prevent burns.

2. 2

   Disconnection

   Locate the Lambda sensor on the exhaust pipe/DPF assembly. Carefully release the locking tab and remove the electrical connector from the Lambda sensor.

3. 3

   Removal

   Using a specialized O2 sensor socket or a 22mm wrench, loosen and remove the Lambda sensor from the exhaust housing.

4. 4

   Installation

   Apply a small amount of anti-seize compound to the threads of the new sensor (if not already pre-applied by the manufacturer). Thread the new sensor in by hand to avoid cross-threading, then tighten to the OEM torque specification.

5. 5

   Reconnection

   Reconnect the electrical connector, ensuring it clicks securely into place. Route the wiring away from extreme heat sources.

6. 6

   ECU Reset

   Connect the CNH diagnostic tool, navigate to the Engine/Exhaust Gas Recirculation electrical system menu, select 'Replacement of the Lambda Sensor – Reset ECU Data', click 'CONFIGURE SELECTED ITEM', and then click 'RESET'.

7. 7

   Verification

   Start the engine, allow it to reach operating temperature, and verify that fault code ENG 3716 does not return.