EMISSION RECALL
IMPCO AUTOMOTIVE
Bulletin Number: 14231
Date: July 2014
SUBJECT:

Incorrect Engine Control Module (ECM) Calibration

MODELS:

2015 Chevrolet Silverado HD
2015 GMC Sierra HD
With Compressed Natural Gas (CNG) System (RPO LC8, FHV)

IMPCO Automotive is conducting this emission recall. For the convenience of our customers,
General Motors has agreed to assist in administering this recall through its Chevrolet and
GMC Dealers.
DEFECT INVOLVED
IMPCO Automotive has decided to conduct a Voluntary Emission Recall involving certain
2015 model year Chevrolet Silverado HD and 2015 model year GMC Sierra HD vehicles
equipped with a compressed natural gas (CNG) system. These vehicles were built with an
incorrect ECM calibration.
SERVICE ACTION REQUIRED
Dealers are to reprogram the engine control module (ECM). The change will allow the vehicle
to operate as originally designed.
VEHICLES INVOLVED
All involved vehicles are identified by Vehicle Identification Number on the Investigate Vehicle
History screen in GM Global Warranty Management system. Dealership service personnel
should always check this site to confirm vehicle involvement prior to beginning any required
inspections and/or repairs. It is important to routinely use this tool to verify eligibility because
not all similar vehicles may be involved regardless of description or option content.
For dealers with involved vehicles, a listing with involved vehicles containing the complete
vehicle identification number, customer name, and address information has been prepared
and will be provided to dealers through the GM GlobalConnect Recall Reports. Dealers will
not have a report available if they have no involved vehicles currently assigned.
The listing may contain customer names and addresses obtained from Motor Vehicle
Registration Records. The use of such motor vehicle registration data for any purpose other
than follow-up necessary to complete this recall is a violation of law in several
states/provinces/countries. Accordingly, you are urged to limit the use of this report to the
follow-up necessary to complete this recall.
Copyright 2013 General Motors. All Rights Reserved.

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July 2014

Bulletin No.: 14231

PART INFORMATION
No parts are required for this recall.
SERVICE PROCEDURE
Note: Carefully read and follow the instructions below.


Do NOT attempt to order the calibration number from GM Customer Care and Aftersales.
The calibration numbers required for this service procedure are programmed into control
modules via a Multiple Diagnostic Interface (MDI) with the calibration update. If you cannot
access the calibration, call the Techline Customer Support Center and it will be provided.



DO NOT program a control module unless directed to by a service procedure or a service
bulletin. If the control module is not properly configured with the correct calibration
software, the control module will not control all of the vehicle features properly.



Ensure the programming tool is equipped with the latest software and is securely
connected to the data link connector. If there is an interruption during programming,
programming failure or control module damage may occur.



Stable battery voltage is critical during programming. Any fluctuation, spiking, over voltage
or loss of voltage will interrupt programming. When required install the EL-49642 SPS
Programming Support Tool to maintain system voltage. If not available, connect a fully
charged 12 V jumper or booster pack disconnected from the AC voltage supply. DO NOT
connect a battery charger.



Turn OFF or disable systems that may put a load on the vehicles battery such as; interior
lights, exterior lights (including daytime running lights), HVAC, radio, etc.



During the programming procedure, follow the SPS prompts for the correct ignition switch
position.



Clear DTCs after programming is complete. Clearing powertrain DTCs will set the
Inspection/Maintenance (I/M) system status indicators to NO.



Note the engine oil life remaining percentage.

To reprogram an existing K20 Engine Control Module, perform the following procedure:
1. Install EL-49642 SPS programming support tool.
2. Access the Service Programming System (SPS) and follow the on-screen instructions.
Refer to Service Programming System (SPS) documentation in SI for programming
instructions.
3. On the SPS Supported Controllers screen, select K20 Engine Control Module Programming and follow the on-screen instructions.
4. Clear DTCs after completing the programming procedure.
Note: If vehicle fails to start during Configuration and Setup, perform the SPS Function
Immobilizer Learn and follow the on-screen instructions.
5. Perform the SPS function K20 Engine Control Module - Configuration & Setup and follow
the on-screen instructions, if available.
6. Clear DTCs after completing the Configuration & Setup procedure.

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July 2014

Bulletin No.: 14231

7. California, Connecticut, Delaware, Maryland, Massachusetts, Maine, Oregon,
Vermont, & Washington vehicles only: Install a Recall Identification Label. Also, for
California vehicles complete a “Proof of Correction” certificate upon recall completion.
RECALL IDENTIFICATION LABEL
For California, Connecticut, Delaware, Maryland, Massachusetts, Maine, Oregon, Vermont,
and Washington Vehicles Only - Place a Recall Identification Label on each vehicle
corrected in accordance with the instructions outlined in this Product Recall Bulletin. Each
label provides a space to include the recall number and the five-digit dealer code of the
dealer performing the recall service. This information may be inserted with a ballpoint pen.
Put the Recall Identification Label on a clean and dry surface of the
radiator core support in an area that will be visible to people servicing the
vehicle.
When installing the Recall Identification Label, be sure to pull the tab to
allow adhesion of the clear protective covering. Additional Recall
Identification Labels for US dealers can be obtained from Dealer Support
Materials
by
ordering
on
the
web
from
DWD
Store,
www.gmglobalconnect.com, and then click on the DWD Store link.
Request Item Number S-1015 when ordering.

GM
RECALL

14231
COMPLETED
DEALER CODE

ED
99-999

DO NOT REMOVE

WARRANTY TRANSACTION INFORMATION
Submit a transaction using the table below. All transactions should be submitted as a ZFAT
transaction type, unless noted otherwise.
Labor
Code
9100621

Description
Engine Control Module Programming with SPS

Labor
Time
0.3

CUSTOMER NOTIFICATION
General Motors will notify customers of this recall on their vehicle (see copy of customer letter
included with this bulletin).
In order to ensure full protection under the emission warranty, and the right to participate in
future recalls, the customer notification letter recommends that customers have their vehicles
serviced as soon as possible. It also advises that failure to do so could legally be determined
to be lack of proper maintenance. The vehicle may fail a state or local emission inspection
test if the recall work is not completed.
DEALER RECALL RESPONSIBILITY
All unsold new vehicles in dealers' possession and subject to this recall must be held and
inspected/repaired per the service procedure of this recall bulletin before customers take
possession of these vehicles.
Dealers are to service all vehicles subject to this recall at no charge to customers, regardless
of mileage, age of vehicle, or ownership, from this time forward.

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July 2014

Bulletin No.: 14231

Customers who have recently purchased vehicles sold from your vehicle inventory, and for
which there is no customer information indicated on the dealer listing, are to be contacted by
the dealer. Arrangements are to be made to make the required correction according to the
instructions contained in this bulletin. A copy of the customer letter is provided in this bulletin
for your use in contacting customers. Recall follow-up cards should not be used for this
purpose, since the customer may not as yet have received the notification letter.
In summary, whenever a vehicle subject to this recall enters your vehicle inventory, or is in
your dealership for service in the future, you must take the steps necessary to be sure the
recall correction has been made before selling or releasing the vehicle.
***THE FOLLOWING 2 PARAGRAPHS ARE NOT FOR CANADA OR EXPORT***
When a California emissions recall is completed by a GM dealer, the dealer must provide the
vehicle owner a “Proof of Correction Certificate” which the owner may need to present to the
California Department Of Motor Vehicles (DMV) when renewing their vehicle registration.
Without this correction certificate, the owner may be unable to renew their vehicle registration.
Additional Certificates can be obtained, at no charge, from Dealer Support Materials by
ordering on the web from the DWD Store, www.gmdealerworld.com, and then click on the
DWD Store link; request GM Item Number 1825 when ordering.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that
may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the tools,
equipment, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to
your vehicle, or that your vehicle will have that condition. See your dealer for information on whether your vehicle may benefit from the information.

We Support
Voluntary Technician
Certification

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July 2014

Bulletin No.: 14231
July 2014

Dear General Motors Customer:
This notice is sent to inform you that IMPCO Automotive is conducting a voluntary emission
recall that includes your vehicle.
Although IMPCO Automotive is conducting the recall, for your convenience, General Motors is
assisting IMPCO by making our dealer network available to perform the recall.
Reason For This Recall: IMPCO Automotive has decided to conduct a Voluntary Emission
Recall involving certain 2015 model year Chevrolet Silverado HD and 2015 model year GMC
Sierra HD vehicles equipped with a compressed natural gas (CNG) system. These vehicles
were built with an incorrect Engine Control Module (ECM) calibration.
What Will Be Done: Your GM dealer will reprogram the Engine Control Module (ECM). This
service will be performed for you at no charge.
What You Should Do: Please contact your GM dealer as soon as possible to arrange a
service date. Instructions for making this correction have been sent to your dealer. Please
ask your dealer if you wish to know how much time will be needed to schedule, process, and
repair your vehicle.
If you have any questions or need any assistance, just contact your dealer or the appropriate
Customer Assistance Center at the number listed below.
Division

Number

Chevrolet
GMC
Guam
Puerto Rico – English
Puerto Rico – Español
Virgin Islands

1-800-222-1020
1-800-462-8782
65-6267-1752
1-800-496-9992
1-800-496-9993
1-800-496-9994

Text Telephones
(TTY)
1-800-833-2438
1-888-889-2438

Emission Law Information: In order to ensure your full protection under the emission
warranty made applicable to your vehicle by state and federal law, and your right to participate
in future recalls, it is recommended that you have your vehicle serviced as soon as possible.
Failure to do so could legally be determined to be lack of proper maintenance of your vehicle.
Also, your vehicle may fail a state or local emission inspection if this recall is not
accomplished.
IMPORTANT MESSAGE FOR CALIFORNIA RESIDENTS
The California Air Resources Board (CARB) requires vehicle emission recalls be completed
prior to California registration renewal. Uncorrected emission recalls will result in the inability
to renew your California vehicle registration.
At the time of emission recall completion, your California dealer will issue a "Proof of
Correction Certificate". Keep this certificate and, if required, present it to the Department of
Motor Vehicles when renewing your California registration as proof of recall completion.

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July 2014

Bulletin No.: 14231

We are sorry to cause you this inconvenience; however, we have taken this action in the
interest of your continued satisfaction with our products.
Jim Moloney
General Director,
Customer and Relationship Services
14231