Solution K40331909
Thursday, February 6, 2020 9:46:21 PM CET

** SOLUTION **
Title

Diesel Exhaust Fluid ( DEF ) Contamination In Fuel System, Inspection And Repair;
Engine Misfire, No-Start, Uneven Operation, Multiple Injector Codes, Fuel Pressure
Codes - US17 And Newer ( Common Rail Fuel System )

Mack Models
LR , MRU - TerraPro , TE - TerraPro , AN - Anthem , CHU - Pinnacle, Axle back , C

Mack Model

XU - Pinnacle, Axle front , GR - Granite , GU - Granite , PI - Pinnacle

Volvo Models
VNL , VNR , VNX , VAH , VHD

Volvo Model

Engine family
Engine family

11L Engine , 13L Engine , MP7 , MP8

** SOLUTION **
In cases where multiple Injector electrical and/or open or short circuit, or high and/or

Cause

low fuel pressure Diagnostic Trouble Codes ( DTC ) have logged, DEF contamination is
a possible cause that should be considered.
Soluti

Overview

on
DEF in the fuel system can cause a multitude of problems. DEF can crystallize in fuel as it warms, which can
result in blockages in several different locations of the fuel system. DEF is also corrosive and will cause
damage to several different types of metal, including carbon steel, brass, aluminum, copper, magnesium, nickel
and zinc. This includes electrical components that DEF comes into contact with. DEF passage through fuel
injectors will normally cause misfires and short or open circuits as the internal components corrode and
become clogged with crystallized DEF. If a chassis has electrical codes (voltage, open circuit, short circuit)
logged for multiple injectors, DEF contamination should be one of the possible causes considered. The
corrosion and buildup of crystal can also cause fuel pressure issues in both high and low pressure circuits as
valves clog or stick in position due to damage caused by the DEF.
For the common rail fuel system, DEF presence in the fuel rail can lead to no-start conditions. Often, low
pressure system pressure will be within spec, but there may or may not be pressure present in the high pressure
system. In addition, it is possible for DEF contamination to be present without any accompanying DTCs, and
the possibility should not be eliminated because of a clear DTC readout if there are symptoms present.

Inspection
There are several locations where the effects of DEF contamination can be observed.

Fuel Tanks
Diesel fuel is less dense than DEF. When allowed to separate, diesel will float on top of DEF which prevents
direct visual confirmation. A sample will need to be taken from the tank.

1. Allow the truck to sit on a reasonably level surface with the engine off for at least one hour to give fuel tank
contents a chance to settle.
2. Using an appropriate clear container (a beaker is a good example), obtain a fuel sample from the bottom of
the fuel tank.
• The depth the sample is taken from is important. Both of the samples in the picture below were taken
from the same tank. A sample taken from the middle or top of the tank (left) may not show an issue,
when a sample taken from the bottom of the tank (right) does.

3. Allow the sample to settle. In many cases there will be a visible separation of DEF and fuel as shown below:

• Shining a light through the sample can help highlight the separation, as seen in the photo.
• Although clear separation may not be present, discoloration or cloudiness of the sample may still
indicate contamination, as seen in the right sample in step 2.

Fuel Filters
1. Remove both fuel filters from the housing.

2. Check for the presence of crystal buildup or corrosion on the filter face as seen below:

Crystal buildup and corrosion/rust present on primary filter

Corrosion/rust on secondary filter

• If the filters are allowed to dry, white crystal residue may be observed on the filter face.

Fuel Injectors
If there are DTCs or symptoms that lead to injector inspection, the Common Rail Injector Electrical Test
should be performed prior to injector removal. If DEF presence is confirmed from another of the checks the
test is not necessary, as the injectors will need to be replaced regardless of the test results.
The low pressure fuel port in the side of the injector may show presence of pitting or crystal deposits as shown
below:

NOTE: When checking for DEF presence on earlier verisons of fuel injectors, it was common to observe a
white haze on the injector body after drying. Common Rail injectors may or may not display this condition
with DEF contamination present, and this check should not be used by itself to conclude that the fuel system is
free of DEF.

Fuel Supply Pump
Corrosion and crystal buildup may be observed in the fuel supply pump as shown below:

Repair
If DEF Is Confirmed To Be Present In The Fuel
The following operations will need to be performed:
• The fuel tanks need to be completely drained and thoroughly flushed with water. The presence of
pitting on the inside of the tank may require tank replacement. The tank will need to be inspected
following cleaning.
• The complete fuel system will need to be thorougly flushed.
• The system should be dried as thoroughly as possible prior to reassembly.
The following parts will need to be replaced:
• Fuel Injectors and sleeves
• Fuel supply pump
• Fuel Filter base
• High pressure fuel supply tubes
• Fuel rail
• Fuel rail pressure sensor
• Fuel rail pressure relief valve
• Fuel return line (from cylinder head to filter housing) assembly
• Aftertreatment Hydrocarbon Injector ( AHI ) Module
• AHI nozzle
• AHI fuel/air supply line (line between AHI module and nozzle)
• Any other fittings where corrosion or clogging is observed.

• NOTE: DEF in the fuel system is a non-warrantable failure.
Solution visibility

Dealer distribution

Function(s)/component(s) affected
Function affected

fuel supply , fuel system , Fuel Dosing

Function Group
Function Group

23 fuel system, excluding gas propulsion , 284 control system, fuel supply

Customer effect
Main customer effect

stumble , regeneration , diagnostics/methodology , efficiency/abnormal behavior , fault
code/display , judder

Fluid problem

crystallisation , contamination , priming/loss of prime

Fluid implicated

Diesel Exhaust Fluid (DEF) , Fuel

Fault Codes And Error Codes
OBDII Diagnostic Trouble

P0087 , P016F , P0201-13 , P0202-13 , P0203-13 , P0204-13 , P0205-13 , P0206-13

Codes (P, U, B Format)

, P0256-14 , P0259-00 , P0262-00 , P0265-00 , P0268-00 , P0271-00 , P0274-00 , P
0277-00 , P1036-00 , P228F , P2A16-14 , P2A19-00 , P2A1E-14 , P2A21-00

Conditions
Vehicle operating mode
Frequency of occurrence of
problem

when driving , when stationary
random

Administration
Author

RU4469V

Dealer ID

RU4469V

Last modified by

RU4469V

Creation date

26-01-2018 16:01

Date of last update

07-01-2020 15:01

Review date

02-02-2019 00:02

Status

Published

Average score

2.5

Number of scores

2

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