New Holland UCM 4782 – UCM: Two speed: Solenoid Supply Short to Ground

The Universal Control Module (UCM) has sent a signal to energize the Two Speed solenoid, but no voltage is detected. The fault becomes active when the Two Speed operating mode is turned on and the solenoid output current (specifically at connector X-CN3A pin 25) registers as high. Two Speed operating mode is disabled while this code is active.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• C227
• C232
• C238
• SR130
• SR150
• SR175
• SV185
• SR200
• SR220
• SR250
• SV250
• SV300
• TR270
• TR320

1. 1

   Connect the Electronic Service Tool (EST) to the machine's service plug to confirm that DTC 4782 is currently active.

2. 2

   Inspect the wiring harness between the UCM and the Two Speed Solenoid for any visible damage, rubbing, or a short to ground in the circuit.

3. 3

   Perform UCM & Solenoid Test: Install a jumper wire between X-2SPD pin A and X-2SPD pin B, reconnect the UCM connectors (X-CN3A), turn the ignition switch ON, and activate the two-speed feature while monitoring the fault code screen on the EST.

4. 4

   Evaluate Test Results: If fault code 4781 is no longer active and fault code 4782 becomes active (Result A), the UCM is functioning properly and the issue is likely the solenoid.

5. 5

   Evaluate Test Results: If fault code 4781 is still active and fault code 4782 did not become active (Result B), the issue is likely an internal failure within the UCM.

1. 1

   Repair or replace wiring harness

   If a short to ground is found during the harness inspection, repair or replace the affected section of the wiring harness. Return to step 1 of the diagnostic checks to confirm the elimination of the fault.

2. 2

   Replace Two Speed Solenoid

   If 'Result A' was achieved during the diagnostic test (fault code 4781 is no longer active and 4782 becomes active), temporarily replace the Two Speed Solenoid and retest the system to confirm the fault is eliminated.

3. 3

   Replace UCM

   If 'Result B' was achieved during the diagnostic test (fault code 4781 is still active and 4782 did not become active), temporarily replace the UCM and retest to confirm the fault is eliminated.