Case IH 19645 – Engine Control Unit (ECU) / Engine Control Module (ECM): Signal range check low error of pressure control valve AD-channel

The Engine Control Unit (ECU) is reading an analog-to-digital (AD) channel signal from the Pressure Control Valve (PCV) that has fallen below the minimum acceptable physical threshold (Signal Range Check Low). This typically means there is an open circuit, a short circuit to ground in the wiring harness, or a complete internal failure of the pressure control valve component.

• Tier 4b
• H50
• CV54
• V710
• Tier 4/Stage 5 engines
• EMR4 engine control systems
• compact tractor
• baler
• auxiliary machine

1. 1

   Inspect the wiring harness connecting the ECU to the Pressure Control Valve for any visible damage, chafing, or pinched wires.

2. 2

   Use a multimeter to test the PCV circuit for a short to ground or an open load (broken wire).

3. 3

   Disconnect the PCV plug and the ECU plug to check for bent pins, moisture, or corrosion.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical spikes during testing.

2. 2

   Locate the PCV

   Locate the Pressure Control Valve, which is typically mounted on the high-pressure fuel pump or the fuel rail.

3. 3

   Harness Testing

   Disconnect the harness from the PCV. Measure the resistance of the wires back to the ECU to confirm continuity. Test the wires against the engine block to ensure there is no short to ground.

4. 4

   Repair Wiring (If Applicable)

   If a broken wire or short to ground is found in the harness, repair or replace the affected wiring section.

5. 5

   Replace the Valve

   If the wiring harness and ECU outputs test perfectly fine, the fault lies within the component itself. Remove the faulty Pressure Control Valve and install a new OEM replacement.

6. 6

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use your electronic service tool (EST) to clear the ECU fault codes. Run the engine to verify the code does not return.