Case IH t36 – Powertrain Control Unit (PCU) / Engine ECU: Boost Air Pressure Sensor (PHY), Data Incorrect

The control module is receiving erratic, intermittent, or implausible data from the turbo boost air pressure (MAP) sensor. The sensor's reading is fluctuating outside of expected parameters or does not correlate correctly with the atmospheric pressure sensor or current engine load.

• MXM
• Case IH MXM120
• Case IH MXM130
• Case IH MXM140
• Case IH MXM155
• Case IH MXM175
• Case IH MXM190
• Case IH Maxxum 110
• Case IH Maxxum 115
• Case IH Maxxum 120
• Case IH Maxxum 125
• Case IH Maxxum 130
• Case IH Maxxum 135
• Case IH Maxxum 140
• Case IH Maxxum 145
• Case IH Puma 150
• Case IH Puma 165
• Case IH Puma 175

1. 1

   Inspect the wiring harness leading to the boost pressure sensor for chafing, melting, or rodent damage.

2. 2

   Disconnect the sensor and check the 4-terminal connector for corrosion, bent pins, or moisture ingress.

3. 3

   Turn the key to the ON position (engine off) and verify that the sensor is receiving the correct 5V reference voltage from the ECU.

4. 4

   Using a diagnostic tool, compare the Boost Pressure Sensor reading to the Atmospheric/Barometric Pressure Sensor reading while the engine is OFF. The readings should be nearly identical. If they are vastly different, the sensor is likely skewed.

5. 5

   Inspect the intake manifold and turbocharger piping for boost leaks, cracked hoses, or blockages that could cause erratic pressure fluctuations.

1. 1

   Turn off the engine, remove the key, and disconnect the negative battery terminal.

2. 2

   Locate the Boost Air Pressure (MAP) sensor on the engine's intake manifold.

3. 3

   Depress the locking tab and carefully disconnect the 4-terminal electrical harness from the sensor.

4. 4

   Remove the two retaining bolts securing the sensor to the manifold.

5. 5

   Pull the sensor straight out. Inspect the port on the manifold for heavy soot or carbon buildup and clean it carefully if necessary (do not push debris into the manifold).

6. 6

   Install the new sensor, ensuring the O-ring/seal is properly seated.

7. 7

   Install and tighten the two retaining bolts.

8. 8

   Reconnect the electrical harness until it clicks into place.

9. 9

   Reconnect the battery, turn the key on, and use a diagnostic tool to clear the t36 fault code.

10. 10

    Start the tractor and verify that the code does not return under load.