Case IH 56042 – Transmission Controller (TRANS): System Pressure Valve Coil circuit is open or shorted to ground when the valve is ON

The system pressure valve solenoid coil has been commanded to turn on, but the voltage on the low side of the coil is lower than expected. This is typically caused by the coil failing open, wiring shorted to ground or open circuit, or no power from the neutral latch relay. If the problem is temperature-sensitive, it is highly likely that the solenoid coil is beginning to fail.

• STX Steiger
• Case IH Puma series
• Case IH Steiger series
• Case IH Magnum series

1. 1

   Visual Inspection: Inspect the wiring harness running from the transmission controller to the system pressure solenoid for any abnormal conditions, rubbing, or breaks.

2. 2

   Coil Resistance Test: Disconnect the system pressure solenoid connector (Connector C039). Measure the resistance of the solenoid coil between cavity A and cavity B. The resistance should be approximately 5.9 to 6.5 ohms at 27°C (80°F). If the resistance is higher than specified, the coil has failed.

3. 3

   Wiring Continuity Test: If the coil resistance is within specification, check the wiring harness for an open circuit or a short to ground between the C039 connector and the transmission controller.

4. 4

   Pressure Sensor Verification: With the engine running at 2000 RPM and connector C039 connected, verify the system pressure sensor reading. If the sensor's reading is not within 70 kPa (10 PSI) of an accurate manual pressure gauge, the pressure sensor is faulty.

1. 1

   Retrieve and Record

   Retrieve, record, and clear any existing fault codes before beginning physical repairs.

2. 2

   Test the Solenoid

   Perform the resistance test on connector C039 as outlined in the diagnostic checks.

3. 3

   Replace or Repair

   If the solenoid coil fails the resistance test, replace the system pressure valve solenoid coil. If the coil passes but the wiring fails continuity/short tests, repair or replace the damaged section of the transmission wiring harness. If the pressure sensor fails the 10 PSI variance test, replace the system pressure sensor.

4. 4

   Reassemble and Clear

   Reconnect all harnesses (note that disconnecting C039 during testing will intentionally trigger codes 56032 or 56042, which is normal). Clear all fault codes from the TRANS controller.

5. 5

   Recalibrate

   Enter the "TRANS SETUP" menu on the display and perform a transmission calibration to ensure the inching pedal and valves are in a valid range.