Case IH 19684 – Engine Control Module (ECM) or Dosing Control Unit (DCU) / SCR Controller: Error set in case of leak test stopped because of break-off conditions

The Selective Catalytic Reduction (SCR) / Diesel Exhaust Fluid (DEF) dosing system leak test (pressure test or purge cycle) was aborted prematurely. This is most commonly caused by operator error (turning off the battery disconnect too soon), electrical interruption, hydraulic failure (massive pressure drop), or extreme temperatures (frozen DEF).

• Tier 4b
• Steiger series (370, 420, 470, 500, 540, 580, 620)
• Magnum series (180, 200, 250, 340, 380)
• Puma
• Maxxum
• Optum series
• Axial-Flow series (5150, 6140, 7140, 7240, 8240, 9240, 7250, 8250, 9250)
• Patriot (4440)
• Titan (3040, 3540, 4040, 4540)

1. 1

   Verify operator shutdown procedure (ensure they wait at least 2 minutes before hitting the battery disconnect switch)

2. 2

   Inspect wiring harness, relays, and fuses supplying power to the DEF Supply Module and DCU for loose grounds or chafed wires

3. 3

   Check DEF tank level, DEF lines, and dosing injector for massive external leaks or heavy white crystallization

4. 4

   Use a diagnostic tool to verify the DEF tank temperature sensor is not falsely reading freezing temperatures

1. 1

   Clear fault code

   Connect the CNH Electronic Service Tool (EST) and clear the fault code.

2. 2

   Prime DEF system

   Turn the key ON and start the engine to allow the DEF system to prime and build pressure.

3. 3

   Perform shutdown procedure

   Turn the key OFF and wait. Listen for the DEF pump running backward. Do not turn off the battery disconnect until the pump completely stops.

4. 4

   Command leak test

   If the code returns without operator interruption, use the EST to manually command a DEF system leak test.

5. 5

   Monitor DEF pressure

   Monitor the DEF pressure during the test. If the pressure drops suddenly or fails to build, inspect the lines.

6. 6

   Replace DEF Supply Module

   If the lines are intact and electrical power is stable, the DEF Supply Module (pump) is failing internally and must be replaced.

7. 7

   Replace DEF main filter

   Whenever replacing the DEF pump, or if contamination is suspected, replace the DEF main filter.