New Holland UCM 4737 – UCM (Universal Control Module): Right Swash Plate Angle Sensor – In-Range Fault

The hydrostatic drive pump uses a swash plate angle sensor to monitor the position of the swash plate, which dictates the speed and direction of the right-side drive motor. An "In-Range Fault" indicates that while the sensor's voltage is within the normal electrical operating limits (it is not completely shorted to ground or shorted to power), the signal being sent back to the controller is erratic, illogical, or the dual internal signals (Right Hand Pump Angle #1 and Angle #2) do not agree with each other.

• L213
• L215
• L218
• L220
• L223
• L225
• L228
• L230
• C227
• C232
• C238

1. 1

   Inspect the wiring harness and connector at the right swash plate angle sensor for corrosion, moisture, backed-out pins, or chafing.

2. 2

   Check hydraulic fluid condition for contamination (milky fluid or degraded oil) which can cause electro-hydraulic control pistons to stick.

3. 3

   Monitor live data for 'Right Hand Pump Angle #1' and 'Right Hand Pump Angle #2' using a diagnostic tool to ensure signals correlate smoothly without dropping out or spiking.

1. 1

   Prepare the Machine

   Park the machine on a level surface, lower the boom completely (or engage the boom lock if it must be raised), and turn off the engine.

2. 2

   Access the Pumps

   Unbolt and tilt the ROPS/cab forward to gain access to the hydrostatic tandem drive pump assembly located in the belly of the machine.

3. 3

   Locate the Sensor

   Locate the right swash plate angle sensor, which is mounted on the side of the right-hand drive pump section (often a Bosch Rexroth A22VG unit).

4. 4

   Remove the Sensor

   Disconnect the electrical harness from the sensor. Remove the mounting screws holding the sensor to the pump housing. (Note: Retain these screws, as replacement sensors typically do not come with new hardware).

5. 5

   Install the New Sensor

   Mount the new swash plate angle sensor and tighten the original screws. Reconnect the electrical harness.

6. 6

   Recalibrate

   Lower and secure the cab. Because a new drive control sensor has been introduced to the UCM, you must perform a Ground Drive Calibration using the machine's instrument cluster or a diagnostic tool so the UCM can learn the new sensor's neutral, full-forward, and full-reverse voltage values.