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Bulletin No.: 15457
Date: September 2015

Service Bulletin

SPECIAL COVERAGE

Subject:	15457 – Diesel Fuel Odor
Models:	2010-2015 Chevrolet Express
	2011-2015 Chevrolet Silverado HD
	2010-2015 GMC Savana
	2011-2015 GMC Sierra HD
	Equipped with 6.6L Duramax Diesel Engine (RPO LML or LGH)

CONDITION

Some 2010-2015 Chevrolet Express and GMC Savana vehicles and 2011-2015 Chevrolet Silverado HD and GMC Sierra HD vehicles that are equipped with 6.6L Duramax Diesel engines (RPO LML or LGH) may contain a leak in the seal between the engine-exhaust down pipe and the engine-exhaust pipe. If a leak is present, the intermittent regeneration of the diesel-particulate filter may cause small amounts of diesel fuel to leak from the vehicle. It may also cause diesel-fuel vapor and engine exhaust to enter the passenger cabin.

SPECIAL COVERAGE ADJUSTMENT

This special coverage covers the condition described above for a period of 5 years or 100,000 miles (160,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.

Dealers are to inspect the turbocharger exhaust pipe and the downpipe connection and implement service kit if necessary. The repairs will be made at no charge to the customer.

For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after September 18, 2015, are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to September 18, 2015, must be submitted to the Service Contract provider.

VEHICLES INVOLVED

All involved vehicles are identified by Vehicle Identification Number on the Applicable Warranties section 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.

PART INFORMATION

Parts required to complete this special coverage are to be obtained from General Motors Customer
Care and Aftersales (GMCCA).

Description	Quantity /Vehicle	Part Number
Gasket, Exhaust Manifold Pipe (4-HOLE Gasket)	1	15126137 General Motors 15126137, Exhaust Pipe Connector Gasket 6.6L diesel. From 01/09/2007, rear. From 01/09/2007, front. $14.00 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-10 / Affiliate links / Images from Amazon Product Advertising API
Pipe, Turbocharger Exhaust	1 (As Req’d)	12643610 GM Adapter $251.74 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-15 / Affiliate links / Images from Amazon Product Advertising API
Clamp, TURBO EXH PIPE	1	97354769 Exhaust Pipe Clamp 2015-16, turbo & exhaust components. 6.6L diesel, turbo & exhaust components. $42.92 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-10 / Affiliate links / Images from Amazon Product Advertising API
Turbo pipe to converter Exhaust Clamp and Gasket Kit	1	22967814 GM Parts Pkg GM Parts Pkg $47.42 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-19 / Affiliate links / Images from Amazon Product Advertising API
Converter (should not be required in most cases)	1 (As Req’d)	22887212 General Motors 22887212, Catalytic Converter Genuine General Motors OEM product $2,275.26 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-15 / Affiliate links / Images from Amazon Product Advertising API

Service Procedure

1. Verify that there is an exhaust leak between the turbocharger exhaust pipe and the downpipe. Refer to the appropriate diagnostic information in SI.
   • If there is NOT an exhaust leak between the turbocharger exhaust pipe and the downpipe, no further action is required. Inform the customer that any additional diagnosis and repairs are not covered under this special coverage.
   • If there is an exhaust leak between the turbocharger exhaust pipe and the downpipe, proceed to step 2.

Warning: Allow the exhaust system to cool down. Burns may occur if the exhaust system is not cooled prior to performing any repairs.

2. Remove and discard the exhaust clamp between the downpipe and the turbocharger exhaust pipe (1) as shown in the illustration above.

3. If the joint has a gap on either the left or right side, loosen or remove the turbo exhaust pipe mounting bolt (1) as shown in the illustration above.

4. Remove and discard the exhaust clamp at the turbo to turbo exhaust pipe (1). This can allow the turbo exhaust pipe to be rotated slightly to close the gap as shown in the illustration above.

5. Loosen or disconnect the four flange mid-joint bolts (1) located after the catalytic converter.

6. Verify that the exhaust pipe hanger at the transmission is mounted in the outer insulator hole as shown in the illustration above.

7. Using a transmission jack, align the exhaust pipe, downpipe and the turbocharger exhaust pipe flanges until all mounting joints and the flanges are flush and parallel with no or minimal load or force applied. This could include adjusting the mounts as necessary, allowing the flanges to sit flush with the exhaust in a neutral state, using care not to compromise clearances around the exhaust.

8. Visually verify the joint has good contact completely around the downpipe and the turbocharger exhaust pipe as shown in the illustration above.

9. After alignment of all the joints, install and tighten a new clamp at the turbocharger (if removed earlier).

10. Install the gasket (1) and updated exhaust clamp (2), and tighten the exhaust clamp between the downpipe and the turbocharger exhaust pipe as shown in the pictures above. When installing, place the gaps of the v-clamp away from the original leak area if possible.
11. If needed, replace the gasket for the four bolt flange mid-joint and tighten.

12. Install the mounting bolt (1). If the mounting bracket was removed, align and install the bracket. If the bolt will not line up, bend or shim the bracket until alignment is possible.

Note: On 2011 trucks – if the ECM calibration has not been updated on or after 6-11-12, update the calibration. This will allow the Tech 2 to be used to perform a stationary Service Regeneration that will activate the hydrocarbon injector.

Note: For 2012-2013 trucks, the Tech 2 can be used to perform a stationary Service Regeneration that will activate the hydrocarbon injector without updating the calibration. For 2014–2015 trucks utilize the GDS 2.

Note: When inspecting for exhaust odor, make sure there are no other diesel vehicles operating nearby. It is very easy to notice another vehicle’s exhaust odor.

13. Verify the concern has been corrected.
    • If the concern is NOT present, no further action is required.
    • If the concern IS still present, the turbocharger exhaust pipe may need to be replaced on trucks built prior to the breakpoints listed below with an updated turbocharger exhaust pipe with a pilot flange. If the turbocharger exhaust pipe on the customer’s vehicle has the new flange, you should not need to replace it. Refer to Turbocharger Exhaust Pipe Replacement in SI.

Note: The illustration above is the updated turbocharger exhaust pipe with a pilot flange.

Note: The illustration above is the turbocharger exhaust pipe without a pilot flange.

Note: In most cases it will not be necessary to replace the exhaust downpipe/catalytic converter assembly for this condition. However, if the mating flange on the exhaust downpipe/catalytic converter assembly is not true it is possible a leak may occur.

14. Verify the mating flange on the exhaust downpipe/catalytic converter assembly is true.
    • If the mating flange is true, no further action is required.
    • If there are gaps the converter may need replacing, but the new gasket should compensate for minor surface variation. It is preferred that the alignment process is attempted prior to replacing the converter. There have been very few cases that required the converter to correct this condition. Refer to Catalytic Converter Replacement (LGH /LML) in SI.

CUSTOMER REIMBURSEMENT – For US  

Customer requests for reimbursement of previously paid repairs to correct the condition described in this bulletin are to be submitted to the dealer by October 31, 2016, unless otherwise specified by state law.  If this is not convenient for the customer, the customer may mail the completed Customer Reimbursement Request Form and all required documents to the GM Customer Assistance Center.  Repairs must have occurred within the 5 years of the date the vehicle was originally placed in service, or 100,000 miles, whichever occurs first.

All reasonable and customary costs to correct the condition described in this bulletin should be considered for reimbursement.  Any questions or concerns should be reviewed with your GM representative prior to processing the request.

When a customer requests reimbursement, they must provide the following:

• A completed Customer Reimbursement Request Form. This form is mailed to the customer or can be obtained through GM GlobalConnect.
• The name and address of the person who paid for the repair.
• Paid receipt confirming the amount of the repair expense, a description of the repair, and the person or entity performing the repair.

IMPORTANT:  GM requires dealers to approve or deny a reimbursement request within 30 days of receipt.  If a reimbursement request is approved, the dealer should immediately issue a check to the customer and submit an appropriate warranty transaction for the incurred expense.  If a reimbursement request is denied, the dealer MUST provide the customer with a clear and concise explanation, in writing, as to why the request was denied.  The bottom portion of the Customer Reimbursement Request Form may be used for this purpose.  If the denial was due to missing documents, the customer can resubmit the request when the missing documents are obtained, as long as it is still within the allowed reimbursement period.

Warranty transactions for customer reimbursement of previously paid repairs are to be submitted as required by GM Global Warranty Management.  Additional information can also be found in Warranty Administration Bulletin 11-00-89-004.

CUSTOMER REIMBURSEMENT – For Canada and Export  

Customer requests for reimbursement of previously paid repairs to correct the condition described in this bulletin are to be submitted to the dealer prior to or by October 31, 2016.  Repairs must have occurred within the 5 years of the date the vehicle was originally placed in service, or 160,000 kilometers, whichever occurs first.

When a customer requests reimbursement, they must provide the following:

• Proof of ownership at time of repair.
• Original paid receipt confirming the amount of unreimbursed repair expense(s) (including Service Contract deductibles), a description of the repair, and the person or entity performing the repair.

All reasonable and customary costs to correct the condition described in this bulletin should be considered for reimbursement.  Any questions or concerns should be reviewed with your GM representative prior to processing the request.

COURTESY TRANSPORTATION – For US and Canada

The General Motors Courtesy Transportation program is intended to minimize customer inconvenience when a vehicle requires a repair that is covered by the New Vehicle Limited Warranties.  The availability of courtesy transportation to customers whose vehicles are within the warranty coverage period and involved in a product program is very important in maintaining customer satisfaction.  Dealers are to ensure that these customers understand that shuttle service or some other form of courtesy transportation is available and will be provided at no charge.  Dealers should refer to the General Motors Service Policies and Procedures Manual for Courtesy Transportation guidelines.

WARRANTY TRANSACTION INFORMATION

Submit a transaction using the table below.  All transactions should be submitted as a ZREG transaction type, unless noted otherwise.

Vehicles Still Covered Under Applicable New Vehicle Limited Warranties

Note: For reimbursements on vehicles covered under warranty, refer to the Policies and Procedures Manual.

Vehicles No Longer Covered Under Applicable New Vehicle Limited Warranties

* The amount identified in “Net Item” should represent the dollar amount reimbursed to the customer.

CUSTOMER NOTIFICATION

General Motors will notify customers of this special coverage on their vehicles (see copy of typical customer letter included with this bulletin – actual divisional letter may vary slightly)

October 2015

This notice applies to your vehicle, VIN: _____________________________________

Dear General Motors Customer:

As the owner of a GM vehicle, your satisfaction with our product is very important to us.

This letter is intended to make you aware that some 2010-2015 Chevrolet Express and GMC Savana vehicles and 2011-2015 Chevrolet Silverado HD and GMC Sierra HD vehicles that are equipped with 6.6L Duramax Diesel engines may contain a leak in the seal between the engine-exhaust down pipe and the engine-exhaust pipe.  If a leak is present, the intermittent regeneration of the diesel-particulate filter may cause small amounts of diesel fuel to leak from the vehicle.  It may also cause diesel-fuel vapor and engine exhaust to enter the passenger cabin.

Do not take your vehicle to your GM dealer as a result of this letter unless you believe that your vehicle has the condition as described above.

What We Have Done:  General Motors is providing owners with additional protection for the condition described above.  If this condition occurs on your vehicle within 5 years of the date your vehicle was originally placed in service or 100,000 miles (160,000 km), whichever occurs first, the condition will be repaired for you at no charge.  Diagnosis or repair for conditions other than the condition described above is not covered under this special coverage program.

What You Should Do:  If you believe that your vehicle has the condition described above, repairs and adjustments qualifying under this special coverage must be performed by a General Motors dealer.  You may want to contact your GM dealer to find out how long they will need to have your vehicle so that you may schedule the appointment at a time that is convenient for you.  This will also allow your dealer to order parts if they are not already in stock. Keep this letter with your other important glove box literature for future reference.

Reimbursement:  If you have paid for repairs for the condition described in this letter, please complete the enclosed reimbursement form and present it to your dealer with all required documents.  Working with your dealer will expedite your request, however, if this is not convenient, you may mail the completed reimbursement form and all required documents to Reimbursement Department, PO Box 33170, Detroit, MI 48232-5170.  The completed form and required documents must be presented to your dealer or received by the Reimbursement Department by October 31, 2016, unless state law specifies a longer reimbursement period.

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	Text Telephones (TTY)
Chevrolet	1-800-222-1020	1-800-833-2438
GMC	1-800-462-8782	1-888-889-2438
Guam	65-6267-1752
Puerto Rico – English	1-800-496-9992
Puerto Rico – Español	1-800-496-9993
Virgin Islands	1-800-496-9994

We are sorry for any inconvenience you may experience; however, we have taken this action in the interest of your continued satisfaction with our products.

Terry M. Inch
Executive Director
Global Connected Customer Experience

Enclosure
15457

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