Case IH 19105 (F-3363-06) - ECU – Engine Control Unit (ECU) / Engine Control Module (ECM): DEF/AdBlue tank heater ECU driver over temperature failure

The internal driver circuit within the control module that supplies power to the DEF (Diesel Exhaust Fluid) tank heater has exceeded its maximum safe operating temperature. This condition is typically the result of excessive current draw, which is almost always caused by a short circuit in the heater element itself or a short to ground in the wiring harness leading to the heater.

• VESTRUM CVX
• Case IH 240 Series Axial-Flow Combines
• 7240
• 8240
• 9240
• Case IH Farmall Tractors
• 40-45-50 CVT
• 115U Efficient Power
• Case IH / New Holland T7 Series (Tier 4B)
• Case IH Steiger / New Holland T9 Series
• T9.480

1. 1

   Check for Companion Codes: Look for active codes that indicate a direct short. Code 19106 frequently accompanies this failure.

2. 2

   Heater Element Resistance Test: Disconnect the electrical connector at the DEF tank heater. Use a multimeter to measure the resistance across the heater element pins. If the resistance is near zero (continuity), the heater element is internally shorted.

3. 3

   Harness Inspection: Inspect the wiring harness between the ECU and the DEF tank heater. Look for chafed wires, melted insulation, or areas where the harness may be rubbing against the frame (causing a short to ground).

4. 4

   ECU Pin Inspection: Disconnect the harness at the ECU and inspect the specific pins for the DEF heater driver. Look for signs of thermal damage, melting, or burning, which would indicate the driver has suffered permanent damage.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent further electrical damage.

2. 2

   Isolate the Short

   Based on the diagnostic checks, locate the source of the excessive current draw.

3. 3

   Replace the Heater (If Faulty)

   If the DEF tank heater element is internally shorted, drain the DEF tank to a clean container. Remove the DEF tank sending unit/heater assembly from the tank and install the replacement unit.

4. 4

   Repair the Wiring (If Faulty)

   If the harness is chafed and shorting to the chassis, repair the damaged wires using OEM-approved heat-shrink butt connectors and re-loom the harness. Ensure it is routed away from sharp edges.

5. 5

   Re-evaluate the ECU

   Reconnect all components and restore battery power. Clear the fault codes using a certified diagnostic tool. Run the machine and command the DEF heater on. If code 19105 immediately returns despite a known-good heater and harness, the ECU's internal driver has been permanently burned out by the over-temperature event, and the ECU will require replacement or professional remanufacturing.