Mechanics

ACCELERATOR PEDAL POSITION SENSOR

2004 GMC Envoy

2004 GMC Envoy 6 cyl Two Wheel Drive Automatic 86000 miles

My accelerator pedal position sensor is bad. The dealership told me the replacement part would cost $260. I consulted an online GMC tech and he said it should cost around $85. I called a few car parts places and found one in NY that was $53 plus shipping.

I called the dealership and told them to order from the NY company. The dealership then told me I needed the entire accelerator sensor assembly!

I called the NY company back to find out how much the whole thing cost and they gave me a price, but then told me 90% of the time only the APPS needed to be replaced!

How can I tell which one I need?
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IamRebelee
June 28, 2010.



Hi IamRebelee. Welcome to the forum. It sounds like you're losing perspective and possibly doing yourself a disservice in the process. Is the $260.00 at the dealership just for the part or does that include labor?

If it's just for the part, consider the person who has to find the part number and order it. It has to get to their shop somehow, and most importantly, if it proves to be defective, it must be shipped back and the process starts over the second time. That is one of the biggest reasons for buying at wholesale and selling at retail. Once those problems crop up, your wallet is out of the picture. As one corporate trainer used to say, " we not only sell you the parts; we sell them to you pre-broken. I've heard way too many stories about someone receiving a defective new part or a different part number than was ordered. Any savings are gone out the window now.

When you order a part from anyone other than the manufacturer you have no way of knowing what kind of quality it will have. Some parts store chains order from the original manufacturer of that part, then rebox it with their own name and part number. Some aftermarket manufacturers reverse engineer the original part in order to duplicate it and might overlook an important detail that compromises some operating characteristic. And to be fooled even more, some aftermarket parts are designed and built to address a common failure in the original part so they are actually better than the original.

Original parts go through a lot of testing. I have a copy of the test results for a.50 part that was approved for use in a Chrysler car radio that caused almost a 100 percent failure rate. There were over five pages of test results for everything from temperature extremes to vibration resistance and stability before that part was approved for use in warranty repairs. That's just one tiny part out of hundreds in a simple car radio. Every part the manufacturer uses is tested that way and they STILL sometimes run into unexpected problems.

When the vehicle is out of warranty, the dealer is free to order that part from any supplier, and they have the most experience at knowing which part is the best value, (not necessarily the best price). Any new part that has to be replaced twice as often is not a bargain if it costs half as much.

One hidden danger of telling the dealer where to order the part from is that problem of getting a defective one, or what if it fails within the warranty period? If you deny them the profit up front, they aren't about to cover the cost of removing it, sending it back, ordering the replacement, arguing about who caused the defect, and installing the new one. You can expect to be billed again for the same service.

Also, you wouldn't bring your own food to a restaurant and ask them to cook it so you could save a few bucks. Sure food costs less from a grocery store but you understand you're paying for and expecting to receive more than just the food. You're paying for the cook's training, the special tools and equipment that you are not expected to supply, and the people who bring the finished product to you and clean up afterwards. Besides the food, you're paying for the service. When I'm feeling too cheap to pay for all of that, I have to do all of that myself at home, and most of the time, that is indeed the better value for me. No one can blame someone for trying to find the best value but a better course of action would be to install the new part yourself.

I understand your question of finding the right part to order, but that is part of the fun of doing the job yourself, (assumming of course you consider it fun to save some money). Having a friend who is a mechanic can help, but you can also take your old part to a parts store to match it up to their new ones. Be prepared with the date of manufacture because redesigned parts can be introduced on the assembly line at any time during the model year. The date of manufacture is printed on a sticker usually found in the driver's door opening.

One last thing to be aware of is the probable need to have your new part programmed to the vehicle. GM started this insanity to prevent parts from stolen cars being reused, but every manufacturer does this now. Everything from a headlight switch to the radio is a computer module that must have the software installed with special equipment and a computer hooked to the internet. That programming is likely to be included in the $260.00 since the part won't work without it. If I'm incorrect for your model year, there will still be a procedure to initailize it to the Engine Computer. Until that is done, there will likely be some issues that will occur until the computer relearns the characteristics of the new sensor. On many Chryslers, for example, specific conditions are met during driving that tell the computer when to relearn things so most problems resolve themselves within a day or two. Chrysler and GM are USUALLY quite similar in the way they do things.

One more thing you might consider is looking for an Automotive program at a nearby community college. Many of the programs are sponsored by manufacturers. At the very least, the instructors receive a lot of retraining during the year and someone is likely to be familiar with your vehicle. Most programs also seek out people willing to let students work on their cars and trucks for the practical experience. The kids are well supervised and the typical labor charge is very tiny. This is a better alternative to risking further damage to parts you're not comfortable working on yourself.

If you do want to tackle this yourself, invest in the service manual right from the manufacturer. There are now many diagnostic manuals too for each different system because there would be too many pages to stuff into one manual. The diagnostic manual walks you through the steps to find and verify the defective part, but it often requires you to use special equipment. The service manual just tells you how to replace and program the part after it has been diagnosed. Together they can save you a lot of money, and they can help you determine when it is best to seek out the help of a professional.

Caradiodoc

Caradiodoc
Jun 28, 2010.