Case IH 17487 (F-522007-31) - ECU – Engine Control Unit (ECU): Short circuit to battery error on low powerstage for Urea back flow pump

The reverting pump is responsible for purging DEF fluid from the lines and returning it to the tank when the machine is shut off to prevent the fluid from freezing and expanding. This code triggers when the control module detects that the driver circuit controlling this pump has shorted to battery voltage.

• VESTRUM CVX
• Axial-Flow 240 series (7240, 8240, 9240)
• Axial-Flow 130 series
• Axial-Flow 230 series
• Magnum
• Steiger
• Maxxum
• Puma
• Farmall
• Patriot series (4430, 3240, 3340)
• Case N-Series Loader Backhoes
• Farmlift Telehandlers

1. 1

   Turn off the ignition switch before disconnecting any components.

2. 2

   Inspect the wiring harness and control circuit running between the ECU/DCU and the DEF Supply Module for chafed wires shorting to a battery voltage source.

3. 3

   Disconnect the DEF pump connector and the ECU connector to check for corrosion, moisture (which can bridge circuits), or pushed-out pins.

4. 4

   If the wiring harness tests good, verify if the short is internal to the DEF Supply Module's reverting pump motor or its internal driver.

1. 1

   Disconnect Power

   Disconnect the machine's battery to prevent further electrical damage during the repair.

2. 2

   Repair Wiring (If Applicable)

   If a short was found in the wiring harness during diagnostics, repair or replace the affected section of the harness.

3. 3

   Clean the Area

   If the wiring is intact and the DEF Supply Module is deemed faulty, thoroughly clean the area around the DEF pump with distilled water before opening any lines. It is critical to remove all dried white urea crust and dirt to prevent contamination of the high-pressure fluid loops.

4. 4

   Replace the DEF Supply Module

   The reverting pump is integrated into the DEF Supply Module (Bosch Denoxtronic unit) and is generally not serviced separately. Disconnect the fluid lines and electrical connectors, unbolt the module from its mounting bracket or tank flange, and install the new unit.

5. 5

   Reassemble and Reconnect

   Reconnect all fluid lines, electrical connectors, and the battery.

6. 6

   Program and Clear Codes

   Use a diagnostic scan tool to clear the fault codes. Note: A new DEF Supply Module will likely need to be programmed/calibrated to the vehicle's ECU after replacement.

7. 7

   System Test

   Run a DEF system test (dosing and reverting test) via the scan tool to verify the pump operates correctly and the code does not return.