New Holland ENG 153 – Engine Controller: Intake Manifold Temperature Sensor voltage is too high.

The Engine Control Unit (ECU) has detected that the voltage signal from the Intake Manifold Temperature Sensor is exceeding the normal operating range (typically greater than 4.93V for more than 500 milliseconds). This almost always indicates an open circuit (a broken wire, disconnected plug, or internally failed sensor) or a short to a 5V/battery power source. When this fault is active, the ECU will typically default to a fixed replacement temperature value (e.g., around 86°F / 30°C) to keep the machine running, which can affect engine performance and emissions.

• T8010
• T8020
• T8030
• T8040
• T3010-T3040
• TD5.75
• CR9090
• CX8080
• CX8090
• FR450
• MX Magnum series
• CVX series
• Steiger

1. 1

   Visual Inspection: Locate the Intake Manifold Temperature Sensor on the engine's intake manifold. Inspect the sensor's electrical connector and the wiring harness leading back to the Engine ECU for chafing, breaks, corrosion, or backed-out pins.

2. 2

   Sensor Disconnect Test: Disconnect the sensor. Check the connector for moisture or dirt.

3. 3

   Wiring Continuity & Short Test: Using a multimeter, check the signal wire and the ground/return wire from the sensor connector back to the ECU harness. Ensure there is continuity and that the signal wire is not shorted to a power source.

4. 4

   Sensor Resistance Test: Measure the resistance across the two pins of the temperature sensor. If the multimeter reads 'OL' (Open Loop) or an extremely high resistance regardless of temperature, the sensor has failed internally.

1. 1

   Power Down

   Turn off the machine and remove the key from the ignition. Disconnect the battery ground cable if you will be repairing wiring.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a broken wire or damaged connector, splice in a new connector pigtail or repair the broken wire using weather-sealed heat shrink connectors.

3. 3

   Replace the Sensor

   Disconnect the electrical harness from the Intake Manifold Temperature Sensor. Using the appropriate deep socket or wrench, unthread the faulty sensor from the intake manifold. Clean the mating threads on the manifold. Thread the new OEM sensor into the manifold and tighten to the manufacturer's specified torque (do not over-tighten, as these are often brass or delicate fittings). Reconnect the electrical harness until it clicks securely.

4. 4

   Verify Repair

   Reconnect the battery, turn the key on, and use a diagnostic scan tool (or the machine's onboard display) to clear the inactive ENG 153 fault code. Start the engine and verify that the code does not return and that the intake temperature reads correctly.