Case IH P36 – PTO / Rear Hitch Control Module (P36) or Engine Control Unit / EDC 7 (T36): Rear PTO Failure To Start - Relay Or Switch Wiring Fault (P36) / Boost Air Pressure Sensor (PHY), Data Incorrect (T36)

Code P36 indicates an electrical failure preventing the rear Power Take-Off (PTO) from starting due to a wiring fault in the relay or switch. Code T36 indicates data from the Boost Air Pressure Sensor is valid but incorrect or implausible for the current engine operating conditions.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190

1. 1

   If diagnosing a PTO fault (Code P36): Inspect the PTO relay coil to ensure it is not shorted to +12 Volts, shorted to ground, or suffering from an open circuit.

2. 2

   If diagnosing a PTO fault (Code P36): Check the wiring between the cab PTO switch, the fender-mounted PTO switch (if fitted), and the relay.

3. 3

   If diagnosing a boost pressure fault (Code T36): Locate the boost air pressure sensor, which is mounted on the intake manifold / suction pipe.

4. 4

   If diagnosing a boost pressure fault (Code T36): Check the sensor's electrical resistance (between terminals 3 and 4 should measure between 3400 and 8200 Ω at 20°C).

5. 5

   If diagnosing a boost pressure fault (Code T36): Inspect the wiring harness for open circuits, shorts to ground, or shorts to a high voltage source.

6. 6

   If diagnosing a boost pressure fault (Code T36): Verify that there are no physical leaks in the turbocharger, intercooler, or intake piping.

1. 1

   Disconnect battery

   If diagnosing Code T36: Turn off the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Locate sensor

   If diagnosing Code T36: Locate the boost air pressure sensor on the engine's suction pipe/intake manifold.

3. 3

   Inspect harness and pins

   If diagnosing Code T36: Disconnect the sensor's electrical harness and inspect the pins for corrosion or damage.

4. 4

   Inspect sensor tip

   If diagnosing Code T36: Remove the sensor and inspect the tip for severe soot or carbon blockage.

5. 5

   Test sensor resistance

   If diagnosing Code T36: Test the sensor's resistance with a multimeter. If it falls outside the 3400–8200 Ω range at room temperature, the sensor is internally faulty.

6. 6

   Replace sensor and clear codes

   If diagnosing Code T36: Install a replacement sensor, reconnect the harness, and clear the fault codes from the ECU.

7. 7

   Verify repair

   If diagnosing Code T36: Run the tractor under load to verify that the boost pressure reads correctly and the code does not return.

8. 8

   Repair PTO relay or wiring

   If diagnosing Code P36: Replace the faulty PTO relay or repair the damaged wiring harness to restore PTO function.