Solution K52535491
Monday, June 3, 2019 6:00:47 PM CEST

** SOLUTION **
Title

Diagnostic / Troubleshooting Procedures For Exhaust Gas Recirculation (EGR) System
Components; Covers Most EGR System Diagnostic Trouble Codes (DTC), See List In
Solution - US10, US10+OBD13, US14+OBD*, US17+OBD* With A Variable
Geometry Turbocharger (VGT)

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

Mack Model

back , CXU - Pinnacle, Axle front , GR - Granite , GU - Granite , PI - Pinnacle , TD Titan

Volvo Models
VNL , VNM , VNR , VNX , VAH , VHD , VT

Volvo Model

Emission Standard
Emission Standard

US10 , US10+OBD13 , US14+OBD13 , US14+OBD15 , US14+OBD16 , US17+OB
D16 , US17+OBD18 , US17+OBD19

Engine family
Engine family

11L Engine , 13L Engine , MP7 , MP8

** SOLUTION **
Cause

Current Guided Diagnostic steps in Premium Tech Tool ( PTT ) begin with electrical
wiring and connector checks for the EGR valve, then move to a Turbocharger Actuator
(VGT, SRA) function test. Field testing has indicated that insufficient flow codes are not
typically caused by electrical issues or EGR valve failure, and these initial electricalrelated checks and inspections can be time-consuming. The new Diagnostic Steps start
with an enhanced review of an EGR Function test during modified test conditions that
will reveal more information in less time. The new procedure has the dual purpose of not
only checking EGR valve function, but also determining EGR cooler condition.

Soluti
on

An eService case is NO
LONGER REQUIRED for this
solution. Repairs should be
performed based on the
findings from the diagnostic
steps below.

If a vehicle has any of the fault codes listed in the fault code section and no obvious
issues are found from a visual inspection, follow the procedure below:

I. Initial Conditions
Begin by starting Operation 2939-08-03-01 Exhaust Gas Recirculation Function under the Test
tab in PTT.
- Coolant temp must remain below 155 °F (68 °C) during this test. The EGR valve is commanded closed
by the Engine Control Module during this time.
- Engine speed should be set to 780-840 RPM using the Cruise Control switch. 800 RPMs is ideal.
• Note that it may be necessary to set engine speed using the accelerator and the SET button initially. From
there the SET and RESUME buttons should work to adjust speed.
• Certain chassis may need to have Maximum Stationary Engine Speed set to 900 before the cruise control
buttons will work to adjust idle.
- VGT position should range between 6% and 14% depending on the coolant temperature.
• It is important that the turbocharger position be in the above range. If the exhaust temperature is
very low, the VGT will open to 40% until the DPF outlet temperature sensor (T3) reaches 140 °F (60 °C).
If the turbo position is greater than 14%, the truck should be allowed to run until position returns to
between 6% and 14% before performing the checks below.

II. Checks
Both steps below should have a screenshot taken showing the parameter list as shown in the
pictures for each step.
1. With initial conditions achieved, turbo speed should be checked when the EGR Position is 0%.
Screenshot : Should be taken with Conditions (in YELLOW ) achieved and showing EGR valve at 0%.

- Turbocharger Speed (in LIGHT BLUE ) should be greater than 35,000 RPM
- If Turbo Speed is less than 30,000 RPM, a sticking EGR valve is possible.
- If Turbo Speed is less than 20,000 RPM, a stuck EGR valve is highly likely
• EGR differential pressure will likely show a value of at least .2 PSI (1.4 kPa).
• The chassis may also generate excessive Parked Regeneration requests or driveability complaints.

2. Activate the EGR valve by pressing the Play button in the EGR Valve Activation box. The
valve should open to 95%.
Screenshot : Should be taken with Conditions (in YELLOW ) achieved and showing EGR valve at 95% just
before the valve closes again OR the engine dies.

- Turbocharger speed should drop below 15,000 RPM within 10 seconds of valve activation.
- If turbo speed does not change, the EGR valve should be checked to confirm it is not stuck closed.
- If turbo speed drops but remains above 20,000 RPM, the EGR cooler is likely plugged.
• A turbo speed reaction to EGR valve activation is a normal indicator of an operational EGR valve.
• The Venturi tube should also be checked to ensure it is free of blockage (Much less likely).
- If turbo speed reacts as expected, the EGR differential pressure sensor or EGR Temperature Sensor are the
likely issue for High or Low Flow codes.
• Check for clogs or excessive condensation in the EGR sensor, sensor supply tubes, or Venturi tube.
• Check for a non-plausible differential pressure value during valve activation.
A negative value or low value, for instance .2 PSI (1.4 kPa) or less, at full valve activation is an
indication of an EGR dP sensor and/or venturi tube issue.
• Check for a non-plausible EGR temperature value during valve activation.
A temperature reading below coolant temperature or higher than exhaust temperature is an indication
of an EGR temperature sensor issue.
Solution visibility

Dealer distribution

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

Diagnostic tool , Turbocharger , EGR

Function Group
Function Group

293 EGR (Exhaust Gas Recirculation)

Customer effect
Main customer effect

diagnostics/methodology , fault code/display

Fault Codes And Error Codes
US10 Fault Codes (SPN-

SPN 412 FMI 15 , SPN 412 FMI 0 , SPN 2659 FMI 18 , SPN 2659 FMI 16 , SPN

FMI Format)

4752 FMI 7

OBDII Diagnostic Trouble
Codes (P, U, B Format)

P0401-00 , P0402-00 , P04DD-00 , P1121-00 , P1121-98 , P2457-00

Conditions
Vehicle operating mode
Frequency of occurrence of
problem

when driving , when stationary
random

Administration
Author

UT9246H

Dealer ID

UT9246H

Last modified by

RU4469V

Creation date

13-02-2018 15:02

Date of last update

07-05-2019 20:05

Review date

15-04-2018 00:04

Status

Published

Average score

1.5

Number of scores

2