Case IH 19096 (DTC 436A) - ECU – Engine Control Unit (ECU): DEF/AdBlue supply module temperature not available

The Engine Control Unit (ECU) is not receiving a valid temperature signal from the sensor located inside the DEF (Diesel Exhaust Fluid) supply module. Because the system cannot monitor the temperature of the DEF fluid at the pump, it cannot safely operate the Selective Catalytic Reduction (SCR) emissions system. This fault will trigger an emissions-related engine inducement, resulting in a severe engine power derate or idle-only mode.

• MAXXUM T4E
• 240 Series Axial-Flow (7240, 8240, 9240)
• 130 Series (5130, 6130, 7130)
• 250 Series
• Steiger (350 to 600)
• Magnum (180 to 370)
• Puma (130 to 240)
• Maxxum (110 to 150)
• Patriot Series (2250, 3240, 3340, 4430)
• Farmlift Telehandlers (632, 635, 735, 742, 935)

1. 1

   Visually inspect the wiring harness and connectors between the Engine ECU and the DEF Supply Module for damaged, bent, or dislocated pins, corroded terminals, or broken wires.

2. 2

   Perform a harness flex test by verifying connectors are fully seated and locked, then flexing the harnesses while monitoring the diagnostic display for intermittent breaks or shorts.

3. 3

   Perform a continuity check using a multimeter and the machine's electrical schematic on the temperature sensor signal and ground circuits between the ECU and the DEF supply module.

1. 1

   Depressurize and Drain

   Ensure the machine is off and the DEF system has completed its purge cycle. Drain the DEF tank if necessary to prevent spills.

2. 2

   Remove the Module

   Disconnect the electrical harness and the DEF fluid lines from the supply module. Unbolt the module from its mounting bracket.

3. 3

   Install New Module

   Mount the replacement DEF supply module. Reconnect the fluid lines and the electrical harness.

4. 4

   Replace Filter

   It is highly recommended to replace the DEF supply module filter element (dosing pump filter) at the same time to protect the new pump from crystallized urea deposits.

5. 5

   Software Programming

   The new module may need to be programmed or calibrated to the vehicle's ECU using the Case IH Electronic Service Tool (EST).

6. 6

   Inducement Unlock (Crucial)

   Because this fault causes an emissions inducement (power derate), the system will not automatically clear the derate just by replacing the part. A technician must perform an "Inducement Unlock / Counter Reset" via the diagnostic software once the fault is resolved.