WORKHORSE CUSTOM CHASSIS SERVICE BULLETIN - 60701-T

[DriVer]

WORKHORSE CUSTOM CHASSIS SERVICE BULLETIN

April, 2007

BULLETIN NO: 60701-T

BULLETIN TYPE: Technical

SUBJECT: Aftermarket Engine System Modifications

MODELS: All Models

This bulletin applies to all Engines but is most specific to 8.1 gasoline engines used in Motorhomes. Most Commercial and Fleet owners do not allow engine system modifications as they better understand the negative results that are possible.

All Workhorse Custom Chassis powertrain systems are certified to meet certain Government emission and durability requirements. It is an extensive, complex and expensive process. The exhaust system, intake system, cooling system, electrical system (including calibration), fuel system, and driveline are all involved in the certification of a powertrain combination. The certification process includes extensive testing and test reporting to certain government Regulatory Departments. Design changes in a powertrain combination require re-certification to assure that the system meets both government and Workhorse Custom Chassis requirements.

Powertrain certification is a joint effort between Workhorse Custom Chassis and the engine manufacturer. The engine is tuned and calibrated to provide maximum economy and durability while meeting regulated emission standards

Any change to the various systems outlined above can result in changed emissions and can cause major engine failure and/or damage to engine emissions control system components. Also, changes can result in lumination of the check engine warning light with false component failure codes. Common false codes caused by aftermarket changes involve the Mass Air Flow sensor or Oxygen sensors as these two sensors are most involved in measuring possible emissions system failure.

Any base engine or engine emissions system component damage or false codes caused by aftermarket changes will not be warranted by Workhorse Custom Chassis.

The following are considered aftermarket installations that can cause engine or emission system damage:
"¢ Any change in PCM, TCM or ECM calibrations.
"¢ Any change or modifications to the engines exhaust system.
"¢ Any change or modification to the air cleaner or intake system.
"¢ Driveline modifications such as changing the rear axle ratio.
"¢ Wiring modifications that could alter the operation of engine control system.
"¢ Installation of emissions components that alter original calibrations.
"¢ Improper flushing of engine crankcase.
"¢ Excessive or improper fuel or oil additives.
"¢ Any modification to fuel tank, pump, or other fuel system component.

Workhorse Custom Chassis Dealers should never change a powertrain system design or calibration. Such action could result in major fines from the EPA (Environmental Protection Agency).

Customers that have modifications made by outside shops should be informed that the changes most often do not provide any significant benefit in fuel mileage and power without resulting in major calibration changes that are detrimental to engine durability and certified emissions control. Damages caused by these changes will not be covered by warranty.

Dealers that suspect that engine or emission damage may be caused by system modification as described above, should contact TAC for resolution. Following are examples where dealer should contact TAC:

"¢ On cases where there is major engine damage, the PCM should not be modified or re-programmed. It should be retained for possible return for electronic analysis to see if calibrations have been changed.
"¢ On cases with repeat Mass Air Flow or O2 sensor codes.
"¢ On cases where there are repeat emission control component replacement.
"¢ On cases where there are repeat check engine codes with no problem found.
"¢ On cases where oil consumption is excessive. (more than one quart per 100 gallons of fuel on gasoline engines)
"¢ Any other suspect case.

GM is the supplier of all current and past Workhorse Custom Chassis Gasoline Engines. Attached is GM Bulletin #04-06-04-054-(01/11/2007) that addresses this same subject. Workhorse Custom Chassis will adopt the GM policies outlined in this bulletin.

---------------------------------------------------------------------------------------------------------------------------

FROM: General Motors Corporation
Authentic Technical Service Information

Document ID# 1886836
________________________________________

Subject: Info - Non-GM Parts and Accessories (Aftermarket) #04-06-04-054A - (01/11/2007)
Models: <LI> 2007 and Prior Passenger Cars and Trucks (Including Saturn)
<LI> 2007 and Prior HUMMER H2, H3
<LI> 2005-2007 Saab 9-7X
________________________________________

This bulletin is being updated to add models and model years. Please discard Corporate Bulletin Number 04-06-04-054 (Section 06 - Engine).
________________________________________

The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these components.

When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM.

During a warranty repair, if a GM original equipment part is not available through GMSPO, ACDelco® distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors.

It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use on a non-GM approved part, the warranty will not be honored.

A good example of non-authorized modification of vehicles is the result of an ever increasing supply of after market devices available to the customer, which claim to increase the horsepower and torque of the Duramax™ Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications:
"¢ Propane injection
"¢ Nitrous oxide injection
"¢ Additional modules (black boxes) that connect to the vehicle wiring systems
"¢ Revised engine calibrations downloaded for the engine control module
"¢ Calibration modules which connect to the vehicle diagnostic connector
"¢ Modification to the engine turbocharger waste gate

Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices.

General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque.

These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty.

Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that results from the alteration or modification of a vehicle using non-GM approved parts or accessories.

Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed.

Any suspect repairs should be reviewed by the Area Service Manager (District Service Manager in Canada) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors.It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle.

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 equipment, tools, 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 GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

© Copyright General Motors Corporation. All Rights Reserved.

[DriVer]

WORKHORSE CUSTOM CHASSIS SERVICE BULLETIN

April, 2007

BULLETIN NO: 60701-T

BULLETIN TYPE: Technical

SUBJECT: Aftermarket Engine System Modifications

MODELS: All Models

This bulletin applies to all Engines but is most specific to 8.1 gasoline engines used in Motorhomes. Most Commercial and Fleet owners do not allow engine system modifications as they better understand the negative results that are possible.

All Workhorse Custom Chassis powertrain systems are certified to meet certain Government emission and durability requirements. It is an extensive, complex and expensive process. The exhaust system, intake system, cooling system, electrical system (including calibration), fuel system, and driveline are all involved in the certification of a powertrain combination. The certification process includes extensive testing and test reporting to certain government Regulatory Departments. Design changes in a powertrain combination require re-certification to assure that the system meets both government and Workhorse Custom Chassis requirements.

Powertrain certification is a joint effort between Workhorse Custom Chassis and the engine manufacturer. The engine is tuned and calibrated to provide maximum economy and durability while meeting regulated emission standards

Any change to the various systems outlined above can result in changed emissions and can cause major engine failure and/or damage to engine emissions control system components. Also, changes can result in lumination of the check engine warning light with false component failure codes. Common false codes caused by aftermarket changes involve the Mass Air Flow sensor or Oxygen sensors as these two sensors are most involved in measuring possible emissions system failure.

Any base engine or engine emissions system component damage or false codes caused by aftermarket changes will not be warranted by Workhorse Custom Chassis.

The following are considered aftermarket installations that can cause engine or emission system damage:
"¢ Any change in PCM, TCM or ECM calibrations.
"¢ Any change or modifications to the engines exhaust system.
"¢ Any change or modification to the air cleaner or intake system.
"¢ Driveline modifications such as changing the rear axle ratio.
"¢ Wiring modifications that could alter the operation of engine control system.
"¢ Installation of emissions components that alter original calibrations.
"¢ Improper flushing of engine crankcase.
"¢ Excessive or improper fuel or oil additives.
"¢ Any modification to fuel tank, pump, or other fuel system component.

Workhorse Custom Chassis Dealers should never change a powertrain system design or calibration. Such action could result in major fines from the EPA (Environmental Protection Agency).

Customers that have modifications made by outside shops should be informed that the changes most often do not provide any significant benefit in fuel mileage and power without resulting in major calibration changes that are detrimental to engine durability and certified emissions control. Damages caused by these changes will not be covered by warranty.

Dealers that suspect that engine or emission damage may be caused by system modification as described above, should contact TAC for resolution. Following are examples where dealer should contact TAC:

"¢ On cases where there is major engine damage, the PCM should not be modified or re-programmed. It should be retained for possible return for electronic analysis to see if calibrations have been changed.
"¢ On cases with repeat Mass Air Flow or O2 sensor codes.
"¢ On cases where there are repeat emission control component replacement.
"¢ On cases where there are repeat check engine codes with no problem found.
"¢ On cases where oil consumption is excessive. (more than one quart per 100 gallons of fuel on gasoline engines)
"¢ Any other suspect case.

GM is the supplier of all current and past Workhorse Custom Chassis Gasoline Engines. Attached is GM Bulletin #04-06-04-054-(01/11/2007) that addresses this same subject. Workhorse Custom Chassis will adopt the GM policies outlined in this bulletin.

---------------------------------------------------------------------------------------------------------------------------

FROM: General Motors Corporation
Authentic Technical Service Information

Document ID# 1886836
________________________________________

Subject: Info - Non-GM Parts and Accessories (Aftermarket) #04-06-04-054A - (01/11/2007)
Models: <LI> 2007 and Prior Passenger Cars and Trucks (Including Saturn)
<LI> 2007 and Prior HUMMER H2, H3
<LI> 2005-2007 Saab 9-7X
________________________________________

This bulletin is being updated to add models and model years. Please discard Corporate Bulletin Number 04-06-04-054 (Section 06 - Engine).
________________________________________

The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these components.

When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM.

During a warranty repair, if a GM original equipment part is not available through GMSPO, ACDelco® distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors.

It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use on a non-GM approved part, the warranty will not be honored.

A good example of non-authorized modification of vehicles is the result of an ever increasing supply of after market devices available to the customer, which claim to increase the horsepower and torque of the Duramax™ Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications:
"¢ Propane injection
"¢ Nitrous oxide injection
"¢ Additional modules (black boxes) that connect to the vehicle wiring systems
"¢ Revised engine calibrations downloaded for the engine control module
"¢ Calibration modules which connect to the vehicle diagnostic connector
"¢ Modification to the engine turbocharger waste gate

Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices.

General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque.

These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty.

Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that results from the alteration or modification of a vehicle using non-GM approved parts or accessories.

Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed.

Any suspect repairs should be reviewed by the Area Service Manager (District Service Manager in Canada) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors.It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle.

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 equipment, tools, 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 GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

© Copyright General Motors Corporation. All Rights Reserved.

[Rocky 2]

Mike, what is your position concerning this notice? I am sure many of us would like your response.

[YosemiteBobR]

Now that DriVer has thrown a big wrench in the works, it sounds like whatever we do GM and/or Workhorse will not cover now, am I right DriVer. This new stand can effect many of us. Not so much the out of warranty operator, but this can also effect extended warranties.

[Geechee]

To all that seem to dislike my thoughts on the subject, it appears WCC and GM are the ones with the last word on the subject of modifications to the Engine Control Modules and fuel systems. It still your MH and you are free to do with it as you wish, but as WCC and GM have now put it in writing " Do so at your on peril". The engine manufactures walk a thin line between governmental regulations,longevity of their products and customer desires for maximum performance/fuel economy. If one decides to push the limits, then they can't be held responsible.

I spent the better part of my years from fourteen until I was thirty-five modifying small blocks Chev's to obtain all they could produce. I did so knowing full well that despite all the bucks spent, the engine was no stronger than its weakest component. Usually that component always made its self known at the most inopportune time.

[Ultra RV Products]

The Magnussen-Moss act is still in effect,this protect's the consumer against the manufacture in the case of a failure,when an aftermarket part is installed.The burden of proof that the aftermarket part caused a failure is still on the vehicle manufacture.If they prove that part to be the cause of a failure they can void the warranty on that part only.

So if you buy your oil filters at Wal-mart to get the CHEAPEST price you could void you warranty!

It's all double talk from legal council,they have been using those statement's long before Workhorse was even thought of.

[Oemtech]

Well now it is official.... during your warranty period don't do any mods. This is nothing new.

Let me get on my soapbox:

So I guess you must put up with an air intake system the sucks water and leaves you on the side of the rode. IE- Don't drive in the rain.

You also must put up with 4k+ rpms hill climbs, sloppy shifting, low hp/tq and poor gas mileage for at least a year.

You better not use a really good 2 qt oil filter either.

Nor shall you add a bottle of Techron to the gas to clean the fuel fuel system.

You will pay $60 for a $10 fuel filter, if you can get one.

Lastly you must leave the Dex Cool in radiator and hope you don't have any problems.

But, after the warranty is over you can correct all of the bad engineering and mistakes done by OEM's.

I will get off my soapbox now.... I feel better now

[YosemiteBobR]

Thanks both Mike and oemtech, we went through this a year or so ago, I had forgotten. I feel better already.

[Marty & Yani]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by YosemiteBobR:
Thanks both Mike and oemtech, we went through this a year or so ago, I had forgotten. I feel better already. </div></BLOCKQUOTE>
Exactly, many things that you don't even think of could void a warranty, even those $29.99 oil change and lube can void a warrenty.
Marty

[Ultra RV Products]

Actually,

In regard's to the ECM it says no calibration changes,we dont change the calibration's,only the perameters within it.The factory abuse modes are still intact.

[Spoonman]

I think the real issue here is people have been told the UP upgrade would not affect their warrantee, and this may not be the case from what I`m reading.

[Geechee]

Mike,

How can you say the calibration has not been changed? GM programed the ECU/ECM with one set of parameters and you said you have "optimized" parameters to increase HP/Torque and fuel mileage. Calibration means the verification that something is functioning within a given set of parameters. By that definition, I submit that what you have said your software accomplishes meets the level of being a change in calibration.

DriVer,

How about getting WCC and GM's take on the subject.

Geechee

[Ultra RV Products]

We are using a GM calibration...Let's say it's a 605 cal file.We dont change it to a 606 or 615 or anything else,we work with what is already there.

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Geechee:
How about getting WCC and GM's take on the subject. </div></BLOCKQUOTE>Geechee, I believe that we have already read what both GM & WCC have published. I don't think that they are going to add much more to the TSI/TSB that are presented here.