Case IH 19098 – Engine Control Module (ECM) or Dosing Control Unit (DCU): DEF/AdBlue supply module heater detected a faulty PWM signal only

The controller detects an irregularity in the electrical circuit (such as an incorrect duty cycle, open circuit, or short) that prevents the heater inside the DEF supply module from operating correctly.

• Tier 4b
• Case IH Puma Series (130, 145, 160, 170, 185, 200, 215, 230)
• Case IH Magnum Series
• Case IH Farmall Series

1. 1

   Inspect the wiring harness and connector between the ECM/DCU and the DEF supply module for corrosion, bent pins, water intrusion, or wire chafing

2. 2

   Use an oscilloscope or a multimeter with duty-cycle capabilities to back-probe the connector at the DEF supply module and verify if the ECM is sending the correct PWM signal

3. 3

   Measure the resistance of the heater element inside the DEF supply module to determine if the internal heater has failed (open or shorted)

4. 4

   Check for OEM software updates, as some erroneous DEF/emissions diagnostic codes are resolved by reflashing the ECM with the latest software revision. (Software issue cause)

1. 1

   Disconnect power

   Turn off the machine's battery isolator switch or disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access DEF supply module

   Locate the DEF supply module (dosing pump), typically mounted near the DEF tank.

3. 3

   Repair wiring harness

   If the diagnostic checks revealed a broken wire or corroded connector, repair the wiring harness or splice in a new connector pigtail.

4. 4

   Replace DEF supply module

   If the wiring is intact and the ECM is sending the correct PWM signal, the heater element inside the supply module has failed. Replace the entire DEF supply module (dosing pump).

5. 5

   Install new module

   Install the new DEF supply module. Reconnect the DEF fluid lines and the electrical harness.

6. 6

   Reprogram ECM

   Reconnect the battery. Connect the CNH Electronic Service Tool (EST) and program/calibrate the new Bosch DEF dosing module to the vehicle's ECM.

7. 7

   Clear codes and test

   Clear fault code 19098 and run an SCR system test via the diagnostic tool to verify the heater is functioning and the PWM signal is recognized.