Case IH 2973 – ENG (Engine Controller / Engine ECU): Intake Manifold 1 Pressure data invalid.

The Engine Control Module is receiving an erratic, out-of-range, or implausible signal from the Intake Manifold Pressure Sensor (also known as the MAP or Boost Pressure sensor). This means the sensor's voltage output does not align with the engine's current operating conditions, indicating either a failed sensor, a wiring issue, or severe contamination blocking the sensor's reading element.

• MX Magnum
• Magnum 215
• Magnum 225
• Magnum 245
• Magnum 250
• Magnum 275
• Magnum 280
• Magnum 305
• Magnum 310
• Magnum 335
• TG Series Tractors
• T8000 Series Tractors
• Puma Series Tractors
• Steiger Series Tractors
• Axial-Flow Combine Harvester 7240
• Axial-Flow Combine Harvester 7250
• Axial-Flow Combine Harvester 8240
• Axial-Flow Combine Harvester 8250
• Axial-Flow Combine Harvester 9240
• Axial-Flow Combine Harvester 9250

1. 1

   Visual Inspection for Contamination: Remove the sensor and check for heavy accumulation of oil, dirt, or carbon/soot deposits that could be blocking the sensor tip.

2. 2

   Wiring and Connector Check: Inspect the 4-pin electrical connector at the sensor. Look for loose connections, backed-out pins, corrosion, or moisture.

3. 3

   Voltage Test: Using a multimeter, verify that the sensor is receiving a steady 5V reference signal and has a solid ground from the Engine ECU.

4. 4

   Intake System Check: Inspect the intake manifold and charge-air cooler piping for severe boost leaks, which can cause pressure readings to fall outside of the expected operational range.

1. 1

   Locate the Sensor

   Locate the Intake Manifold Pressure Sensor on the engine's intake manifold (usually mounted on the top or side of the manifold housing, post-turbocharger).

2. 2

   Disconnect Battery

   Disconnect the machine's battery ground to prevent electrical spikes during replacement.

3. 3

   Disconnect Harness

   Unplug the 4-pin electrical harness connector from the sensor.

4. 4

   Remove the Sensor

   Remove the retaining bolt(s) holding the sensor to the manifold. Carefully pull the sensor straight out.

5. 5

   Clean the Port

   Wipe the mounting port on the intake manifold clean, ensuring no debris falls into the engine intake.

6. 6

   Install New Sensor

   Lubricate the O-ring/seal on the new sensor slightly to prevent tearing. Push the new sensor firmly into the manifold port.

7. 7

   Secure and Reconnect

   Reinstall the retaining bolt(s) and tighten to OEM torque specifications. Reconnect the electrical harness until it clicks into place.

8. 8

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use a diagnostic scan tool to clear fault code 2973. Start the engine and verify that the code does not return.