New Holland DCU 19002 – DCU (Dosing Control Unit): Battery voltage sensing (electrical) | signal low | Battery voltage evaluation below lower limit.

This code indicates that the control module is detecting a supply voltage that has dropped below the minimum acceptable threshold required for normal operation.

• New Holland T7 Series Tractors
• New Holland T8 Series Tractors
• New Holland T9 Series Tractors
• New Holland CR Series Combines
• New Holland CX Series Combines
• New Holland Wheel Loaders (e.g., W190B)

1. 1

   Test the main battery voltage and the alternator charging output to ensure the machine's core electrical system is producing adequate voltage under load.

2. 2

   Check the specific voltage reaching the DCU connector by measuring the battery voltage directly at the DCU pins (pins 47 and 48 for +BAT constant power, and pin 20 for the switched ignition line).

3. 3

   Inspect the wiring harness connecting the battery/power distribution center to the DCU for corrosion, chafing, or loose connections that could cause a voltage drop.

4. 4

   Inspect all fuses and relays associated with the DCU and the SCR/DEF system for blown filaments or high resistance.

1. 1

   Clean Connections

   Clean and tighten the main battery terminals, alternator connections, and chassis ground straps. Poor grounds are a leading cause of low voltage codes.

2. 2

   Replace Fuses/Relays

   If any DCU-related fuses are blown or relays are sticking, replace them and re-test the system.

3. 3

   Repair Wiring

   If your multimeter shows a significant voltage drop between the battery and the DCU connector, trace the wiring harness and repair or replace the damaged section.

4. 4

   Replace Alternator/Battery

   If the machine's overall system voltage is low (failing to maintain proper voltage while running), replace the failing battery or alternator.

5. 5

   Replace the DCU

   If the supply voltage at the DCU connector is perfectly within spec (matching battery voltage) but the DCU still logs code 19002/P0562, the DCU has an internal hardware failure and must be replaced. Note: A new DCU requires software installation and calibration by an authorized dealer.