Case IH 19002 – DCU (Dosing Control Unit): Battery voltage sensing (electrical) | signal low | P0562 Battery voltage evaluation below lower limit

The control module has detected that the system voltage supplied to it has dropped below the acceptable minimum operating threshold. This is usually caused by a failing battery, a weak alternator, or high resistance (corrosion/loose connections) in the wiring harness supplying power to the module.

• Tier 4a
• Tier 4b
• Magnum (235–340 Series 4)
• Steiger (350–600)
• Puma
• Maxxum
• Farmall
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230

1. 1

   Measure the battery voltage at the terminals with the engine off (should be ~12.6V) and with the engine running (should be ~13.5V - 14.5V).

2. 2

   Locate the DCU and disconnect its wiring harness. Inspect the connector for water ingress, bent pins, or green corrosion.

3. 3

   Using a multimeter, measure the voltage at the power supply pins on the DCU connector with the key ON. If the voltage here is significantly lower than the battery voltage, the issue is in the wiring.

4. 4

   Check the main power relays and fuses in the power distribution box that supply the SCR/DCU system. Look for blown fuses, corroded relay terminals, or loose ground straps.

1. 1

   Secure the Machine

   Park the machine on a level surface, turn off the engine, and remove the key.

2. 2

   Resolve Base Electrical Issues

   If the battery failed a load test or the alternator is undercharging, replace the faulty component and clear the codes.

3. 3

   Clean and Repair Wiring

   If the voltage at the DCU connector was low, trace the wiring harness back to the battery/fuse box. Clean any corroded ground terminals to the chassis. Replace any faulty relays or blown fuses supplying the DCU.

4. 4

   Clean the DCU Connector

   If moisture or light corrosion is found in the DCU connector, clean it thoroughly with electrical contact cleaner and apply dielectric grease before reconnecting.

5. 5

   Replace the DCU (If Necessary)

   If the battery, alternator, and wiring harness are all delivering perfect voltage to the DCU connector, but the 19002 (P0562) code remains active, the DCU has an internal hardware failure.

6. 6

   Software Calibration

   If replacing the DCU, the new module must be programmed. CNH requires software installation and specific passwords to commission a new DCU.