Case IH 2693 – ZTC: ZTC - Primary transmission oil filter is restricted

This code indicates that the primary transmission oil filter has reached a high level of restriction. This is typically caused by a clogged filter full of debris, extremely cold and viscous transmission fluid, or a malfunctioning filter restriction switch/sensor falsely reporting a blockage. When restricted, the transmission may not receive adequate hydraulic flow and pressure, which can lead to poor performance or secondary damage.

• Steiger T4B
• Case IH Steiger CVT series
• Case IH Magnum CVX / CVXDrive series
• Case IH Puma CVX series
• Case IH Optum CVX series

1. 1

   Warm up the machine: Cold hydraulic/transmission oil is thick and can trigger a false restriction code. Bring the tractor up to normal operating temperature to see if the code clears.

2. 2

   Check the fluid level: Ensure the transmission hydraulic oil is at the correct level on the dipstick/sight glass.

3. 3

   Test system pressure: Connect a gauge to the transmission system test port. (Normal operating pressure on many Case IH CVT/Powershift systems should be around 12-14 BAR at 1500 RPM with warm oil).

4. 4

   Inspect the Restriction Switch and Wiring: Locate the primary transmission oil filter restriction switch. Check the wiring harness and connector for damage, corrosion, or a short to ground (a common cause of false restriction codes on power-up).

1. 1

   Park and Secure

   Park the tractor on a level surface, engage the parking brake, and turn off the engine.

2. 2

   Relieve Pressure

   Allow the machine to cool slightly and relieve any residual hydraulic pressure.

3. 3

   Locate the Filter

   Locate the primary transmission oil filter housing (usually mounted on the side or rear of the transmission housing, depending on the specific tractor model).

4. 4

   Drain/Catch Fluid

   Place a suitable drain pan under the filter housing to catch any oil loss.

5. 5

   Replace the Filter

   Unscrew the restricted primary transmission oil filter. Lubricate the seal of the new OEM filter with clean transmission oil and install it, tightening to the manufacturer's specified torque.

6. 6

   Service the Sensor (If necessary)

   If diagnostics pointed to a failed sensor rather than a clogged filter, unthread the restriction switch from the filter housing and install a new one. Splice in a new connector if the wiring was damaged.

7. 7

   Refill and Bleed

   Top off the transmission fluid using the approved CNH fluid (e.g., CNH MAT3521 specification).

8. 8

   Test

   Start the tractor, allow it to reach operating temperature, and verify that the ZTC 2693 fault code has cleared and does not return under load.