GM Throttle Body Problems
GM Throttle Body Special Policy Letters
Throttle body and throttle position sensor problems are an increasingly common issue. You can tell you’re having this problem when you see a check engine light, the engine runs rough, or if the engine reduced power message comes on.
Here we’ll discuss the problem specifically for the Cadillac version of the 3.6 L V-6 engines. However, the throttle body used in this engine is similar to the model used on a massive amount of General Motors cars and trucks.
Therefore, even if you don’t have a Cadillac or a 3.6L V-6 you might benefit from the information contained in this article. Here we’ll talk about the problem. Also see if extended coverage under the manufacturers warranty applies to you. Finally, review tips for getting it covered or how to fix it yourself if all else fails.
Drive-by Wire Throttle Body
Long gone are the days of stepping on the gas pedal and moving a throttle cable to open the throttle plates. This simple mechanical connection worked for 100 years with literally no problems. Unfortunately, technology marches forward and car makers needed to control the throttle body in a different way.
With traction control, stability track, collision avoidance and adaptive suspension systems the computer wants to control throttle position. They once entrusted this to the driver, but in a world filled with distractions, car companies decided to intervene. Don’t get me wrong, these safety improvements prevent a lot of accidents and certainly have merit. And you can’t have a self driving car without drive-by wire.
The problem comes when the car companies install sensors and automotive computer controls on mass produced products that don’t stand the test of time. Even worse is when these components last long enough to survive through the warranty period and then wind up in the lap of car owners when they fail past the warranty date. The General Motors throttle body is an excellent example of this issue.
The throttle body assembly is a self-contained unit. It opens and closes the throttle using electronic signals to control an actuator. Throttle position is reported using a TPS (Throttle Position Sensor). This component is also built into the self contained unit. Therefore if any failure occurs with the actuator or sensor, replacing the complete assembly is necessary.
General Motors Special Policy Letter
With the amount of failures of the GM throttle body reaching epic proportions Cadillac decided to get out in front of the issue. They sent me a special policy letter for my 2009 Cadillac SRX with a 3.6 L V-6. Paraphrasing from the letter it says: as the owner of a 2009 model year Cadillac SRX your satisfaction with our product is very important.
This letter is intended to make you aware that on some 2009 3.6L engines the throttle position sensor may cause the engine to run rough or illuminate the check engine light. This might be accompanied by the illumination of the reduced power message indicator. On my particular Cadillac SRX, GM stated the condition will be repaired for me at no charge. Extension of the warranty on this item is for 10 years or 120,000 miles, whichever occurs first. I also received a special policy letter on the timing chain.
Implementation of the Special Policy
I appreciate the fact that General Motors wants to do the right thing and repair cars with the defective throttle bodies. Unfortunately, diagnosis, confirmation and implementation of the no charge repairs are left up to individual dealerships. Despite the fact the dealer would get reimbursed if they replaced the part, no questions asked, it can be difficult to have them agree to cover the repairs.
General Motors under compensates dealers for warranty repairs. This is kind of like a Medicaid patient going into a doctor. The doctor see’s you, but he won’t be real happy about getting paid $14 for an hour’s worth of work. It’s the same way in the car dealership service department. They get reimbursed pennies on the cash dollar for auto repairs. In other words, they’re motivated to find another cause of your problem or additional repairs that require services not covered under warranty.
I’m not saying you can’t get the repairs covered under warranty as stated in the General Motors special policy letter. However, your vehicle will have to meet strict requirements. Specifically, a check engine light code for a throttle position sensor error. An example is a code P2135 through P2140. This series of codes indicate problems within the self-contained throttle body unit and its components. You often see codes like P1516 on older vehicles.
What to do If They Won’t Cover It
If you received a special policy letter make sure you make a copy and retain it for your own records. Then have the dealership attach it to the repair order that you signed. If the dealership says they will not cover the repairs, document their reasons why. Contact your GM division’s customer service department. Provide them with the repair order numbers and documentation listed above.
My advice to people dealing with customer service and the dealership is to remain calm. In fact, the more they think you might buy another vehicle from them the more likely they are to render assistance. If you scream and tell them you hate their vehicles you probably won’t get very far. Tell them you support their brand and look forward to purchasing more GM products. This provides a better chance of gaining assistance.
Fix the Problem Yourself
When all else fails, what should you do? If you have some do-it-yourself skills replacing the throttle body is not a difficult operation. It boils down to four bolts and one electrical connection. This can save you hundreds of dollars over having the dealership perform the repairs for you. There’s also no need to purchase the throttle body from the dealership as this is the most expensive place to buy the component.
Amazon sells most General Motors throttle bodies for less than $150. If something goes wrong, they have a liberal return policy. It seems when people start having a problem with the throttle body, mechanic’s start lining up to service and clean a unit that needs replacing. In most cases a throttle body service will not fix internal problems that illuminate the reduced power light or set check engine light codes. Next up is a list of other common Cadillac problems we’ve talked about.