Repeat Occurrences or Troubleshooting Exhausted: Fault Codes 1682, 3574, and 3596.

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Technical Service Bulletin
Technical Service Bulletin:
Released Date: 06-Aug-2018
TSB180095
Repeat Occurrences or Troubleshooting Exhausted: Fault Codes 1682, 3574,
and 3596.

Repeat Occurrences or Troubleshooting
Exhausted: Fault Codes 1682, 3574, and 3596.
Warranty Statement
The information in this document has no effect on present warranty coverage or repair
practices, nor does it authorize TRP or Campaign actions.

Contents
Product Affected
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•
•
•
•
•
•
•
•

ISB6.7 CM2250
ISB6.7 CM2350 B101
ISC8.3 CM2250
ISL9 CM2250
ISL9 CM2350 L101
ISX12 CM2350 X102
ISX12/ISX11.9 CM2250
ISX15 CM2250
ISX15 CM2350 X101

Issue
Symptom:
• Repeat occurrences of Fault Codes 1682, 3574, or 3596.
• Diesel exhaust fluid (DEF) pressure issues can appear to be on a “timer” with a
certain amount of hours or miles before the fault codes become active.
• Troubleshooting might have been exhausted and DEF system might perform well in
the shop.

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• Multiple aftertreatment diesel exhaust fluid (DEF) dosing units might have been
replaced but fault code 1682, 3574, or 3596 occurrences persist.
• DEF tank might have been cleaned but problem persists.
Root Cause:
• DEF system is contaminated with debris.
• In some instances, DEF tanks are cleaned and DEF dosing units or intake lines are
flushed or even replaced, but these actions are not performed simultaneously.
Subsequent testing or operation between component cleaning causes cross
contamination of previously cleaned components and repeat fault code occurrences.
Verification
If any combination of symptoms listed in Issue section are present, proceed to Resolution
section below.
Resolution
Debris can impact DEF pressure and aftertreatment DEF dosing unit performance in two
ways:
1. Debris builds up in intake fitting screen of aftertreatment DEF dosing unit and
restricts flow into pump. Debris can be paper, fibers, or smaller particles of sand,
rock, or dirt that build up over time.
◦ Visual inspection of intake fitting screen alone might not identify this issue. At
key off, purge cycle can push debris out of intake screen and into intake line or
DEF tank head.
◦ DEF dosing unit suction test is intended to evaluate pump performance and
can only detect a blocked intake fitting that is 100 percent blocked.
◦ DEF dosing unit intake restriction test will not identify this issue even if the
fitting is restricted at time test is performed, because the intake fitting is
downstream of restriction measurement.
2. Debris collects on the pump intake valve in aftertreatment DEF dosing unit and
prevents the intake valve from sealing properly. This form of debris will be small
because debris has to pass through the 103 micron aftertreatment DEF dosing unit
intake screen to get to the intake valve. Particles larger than 40 microns can cause
pump performance issues (a human hair is approximately 50-70 microns wide).
◦ Inspection of DEF through tank fill port is only intended to catch gross
contamination of system.
◦ If debris is present on the pump intake valve of DEF dosing unit, the DEF
dosing unit suction test will fail. Debris can cause intermittent pressure

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fluctuations as it moves on and off of intake valve, and the DEF dosing unit
suction test might pass even though debris is present in the system.

Figure 1, Example of Debris Found in Intake of DEF System Causing Flow Blockage.
1. Paper debris.
2. Aftertreatment DEF dosing unit intake fitting screen.

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Repeat Occurrences or Troubleshooting Exhausted: Fault Codes 1682, 3574, and 3596.

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Figure 2, Typical Operation of Diaphragm Style Pump in Aftertreatment DEF Dosing
Unit.
1.
2.
3.
4.

Intake valve (membrane style).
Outlet valve (membrane style).
Pump diaphragm.
Location where debris builds up causing intake valve not to seal.

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Repeat Occurrences or Troubleshooting Exhausted: Fault Codes 1682, 3574, and 3596.

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Figure 3, Debris Build Up on Aftertreatment DEF Dosing Unit Pump Intake Valve Plate.
Intake Membrane (Valve) Seals Over this Plate On Pump Pressure Stroke.
1. Debris causing pump performance issue. This is what is flushed out when
performing dosing unit non-air flush.
2. Loose debris that settled on the edge of the valve plate.
Perform following steps simultaneously:
• Drain DEF tank and discard DEF. See equipment manufacturer service information.
• Steam clean inside of DEF tank and then rinse thoroughly with clean water. If the
design of the tank does not allow all of the water to drain out, use a wet/dry shop
vacuum to remove any remaining water. Make sure any vacuum attachments used
are clean.
• Inspect the inside of the tank and verify there is no remaining debris.
• Remove and discard DEF tank filter.
• Rinse DEF tank header and flush tank header pickup tube with clean water.
• Flush intake line with clean water.
• Remove and replace aftertreatment DEF dosing unit intake fitting. Before removing
intake fitting, verify area around fitting on aftertreatment dosing unit is clean so dirt is
not knocked into intake port.

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• Remove and discard aftertreatment DEF dosing unit filter. See corresponding
Service Manual. Reference Procedure 011-060 in Section 11.
• Perform aftertreatment DEF dosing unit non-air flush three times. See corresponding
Service Manual. Reference Procedure 011-058 in Section 11.
• Perform the aftertreatment diesel exhaust fluid dosing unit suction test. See
corresponding Service Manual. Reference Procedure 011-121 in Section 11. If out of
specification, replace the DEF dosing unit. See corresponding Service Manual.
Reference Procedure 011-058 in Section 11.
• Install new DEF dosing unit filter. See corresponding Service Manual. Reference
Procedure 011-060 in Section 11.
• Install new DEF tank filter. See equipment manufacturer service information.
• Reassemble DEF tank, DEF tank header, and reconnect intake line. See equipment
manufacturer service information.
• Fill DEF tank with clean DEF.
Other Considerations:
• If shop tap water is cloudy or contains visible impurities, flush internal DEF system
components with bottled or distilled water.
• For optimal DEF system reliability, Cummins Inc. recommends using a 40 micron
DEF tank filter with gradient depth filter media. If the DEF tank does not have a 40
micron gradient depth filter, contact original equipment manufacturer (OEM) or DEF
tank manufacturer for part availability.

Document History
Date
2018-7-11

Details
Module Created

Last Modified: 06-Aug-2018

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8/16/2018