Case IH 12967 – MTA CCM & APH Stage V MR: YES - Faulty input information regarding Supply pressure

The control module is receiving an invalid, missing, or out-of-range electrical signal from the pneumatic supply pressure sensor.

• MAXXUM T4E
• CASE IH Farmall 115U Efficient Power
• Case IH Farmall 40, 45, and 50 Tractors (Cab and CVT Transmission models)

1. 1

   Verify actual air pressure using a mechanical pressure gauge to ensure the air compressor and unloader valve are building and maintaining correct pneumatic supply pressure in the reservoir.

2. 2

   Inspect the wiring harness leading to the Wabco supply pressure sensor for chafing, corrosion, or loose connector pins.

3. 3

   Check for underlying CAN communication faults, as Wabco pneumatic modules communicate via the CAN bus.

4. 4

   Verify that the sensor is receiving the correct reference voltage (power supply) from the CCM.

1. 1

   Depressurize the System

   Safely park the tractor on level ground, turn off the engine, and completely bleed all compressed air from the pneumatic reservoirs to prevent injury.

2. 2

   Locate the Sensor

   Locate the faulty supply pressure sensor, which is typically threaded into the Wabco air manifold, unloader valve, or directly on the air reservoir tank.

3. 3

   Disconnect Electronics

   Carefully unplug the electrical connector from the pressure sensor.

4. 4

   Remove the Sensor

   Unthread the faulty pressure sensor from the pneumatic port.

5. 5

   Install the New Sensor

   Thread the replacement sensor into the port. If it does not have pre-applied thread locker, use an approved pneumatic thread sealant. Tighten to the OEM torque specification.

6. 6

   Reconnect and Test

   Plug the electrical connector back in. Start the tractor and allow the air compressor to build system pressure. Spray soapy water around the sensor threads to ensure there are no air leaks.

7. 7

   Clear Codes

   Use a diagnostic tool to clear fault code 12967 from the MTA CCM & APH module and verify it does not return.