Case IH 15939 - 06 - CSM – CSM: Cab suspension left valve - cab suspension left valve current high

The control module is detecting that the electrical current flowing to the left cab suspension valve solenoid is exceeding the maximum allowable specification. This is typically caused by a short circuit to ground in the wiring harness or an internal short within the valve's solenoid coil itself.

• MAGNUM AFS Connect
• Case IH Magnum series (e.g., Magnum 340)
• Case IH Puma series (e.g., Puma 210)
• Case IH Steiger series

1. 1

   Visually inspect the wiring harness leading from the CSM to the left cab suspension valve for chafed wires, melted insulation, or pinch points where the wire might be shorting to the tractor's chassis.

2. 2

   Disconnect the harness at the left cab suspension valve and inspect the pins for corrosion, moisture, or damage that could cause a short across the terminals.

3. 3

   Using a multimeter, measure the resistance (Ohms) across the pins of the left cab suspension valve solenoid. If the resistance is reading at or near 0 Ohms, the solenoid is internally shorted.

4. 4

   With the valve and the CSM disconnected, test the signal wire for continuity to ground. If there is continuity, the wiring harness has a short and needs to be repaired.

1. 1

   Safety First

   Park the tractor on a level surface, engage the parking brake, and turn off the battery disconnect switch. Ensure the cab is properly supported if the suspension system needs to be depressurized.

2. 2

   Relieve Pressure

   Safely relieve the hydraulic or pneumatic pressure from the cab suspension system according to standard safety practices.

3. 3

   Disconnect Electrical

   Unplug the electrical connector from the faulty left cab suspension valve.

4. 4

   Remove the Valve

   Clean the area around the valve to prevent dirt from entering the system. Loosen and remove the hydraulic/pneumatic lines connected to the valve, capping them immediately. Unbolt the valve from its mounting bracket.

5. 5

   Install the New Valve

   Mount the replacement valve and torque the mounting bolts. Reconnect the hydraulic/pneumatic lines.

6. 6

   Reconnect Electrical

   Plug the wiring harness back into the new valve solenoid.

7. 7

   Test and Clear Codes

   Turn the battery power back on, start the machine, and allow the cab suspension to pressurize and level. Use a diagnostic scan tool to clear the 15939 - 06 fault code from the CSM and verify it does not return during operation.