October_2021 - 43

* SERVICE INFORMATION
SYSTEM / WIRING DIAGRAMS
* SCAN TOOLS
* NOID LIGHT
* DIGITAL MULTIMETER
* BACK-PROBE KIT
* EGT SENSOR SOCKET
* IPR CONTROLLER
* PAPER TOWEL ROLL
to the failure of the sensor. The sensor
was replaced using my favorite 1/4 " drive
set from SK Tools and a road test was
performed to verify the integrity of the
repair. Utilizing the right combination of
information and up-to-date tooling and
techniques allowed for a quick confirmation
of fault and repair with a quick return
to service for the customer.
CASE STUDY 2: 2011
CHEVROLET SILVERADO 3500HD
6.6L (LGH) - REDUCED POWER
AND FAILURE TO REGEN
Failure of a diesel particulate filter
(DPF) to regenerate properly can be a
frustration for both the customer and the
technician. Diesel emissions control systems
are becoming increasingly complex
and therefore harder to diagnose given
the multitude of inter-related systems
and sensor inputs. The amount of data
available makes it easy to overlook readings
that may prove to be incredibly useful
in correcting customer complaints
quickly and effectively. As always, sound
foundational knowledge of base system
operation and access to the appropriate
service information systems, be it OEM
service portals or aftermarket providers
such as Motologic, ProDemand, or
AllData (for example, AllData has a large
selection of OE diagrams within their
software) make the job substantially
easier. The customer's complaint was
a familiar one for anyone working on
p Figure 2 - Cornwell Tools SLC15360 EGT sensor socket.
later model emissions engines: engine
de-rate and an inability to complete a
regeneration event.
For this vehicle, I opted to utilize the
OE tooling for the truck, in this case,
the Tech 2, and perform a preliminary
evaluation which yielded two diagnostic
trouble codes (DTCs): P2463 DPF soot
accumulation and P0571 brake switch circuit
1. A few minutes in SI (service information)
confirmed the code set criteria
and the most useful data parameters to
monitor. Scan data showed 86 grams of
soot accumulation within the DPF and
made it clear that this was an ongoing
problem. Without delving too deeply into
the diagnostic process, a quick check with
my digital multimeter (DMM) of choice,
the Snap-on Vantage, confirmed that
the brake pedal position (BPP) switch
was not operating correctly and as a
result, the engine computer was seeing
a regen abort signal. After replacing the
switch, once again going to my SK Tools
1/4 " drive set, the dashboard displayed
" Cleaning Exhaust Filter Keep Driving
Until Message Is Cleared. " Within three
to five minutes of driving the engine
entered reduced power mode again.
A service regeneration was then
attempted in the parking lot utilizing
the Autel Ultra and monitoring the
data showed that despite throwing no
DTC's, EGT2 (exhaust gas temperature
2) was going open circuit intermittently
and causing the regeneration to abort.
EGT sensors can be difficult to remove
at times, especially in the great NorthEast
with our love of copious amounts of
rock salt and brine. Grabbing a Cornwell
Tools EGT sensor socket from my kit
allowed me to remove the old sensor
with ease and quickly install the new
one (Figure 2).
www.VehicleServicePros.com OCTOBER 2021 PROFESSIONAL TOOL & EQUIPMENT NEWS 43
p Figure 1 - TEXA Axone Nemo 1.
http://www.VehicleServicePros.com
October_2021

Table of Contents for the Digital Edition of October_2021
