You're assuming way too much. With most failures in the electronic throttle body system, engine speed won't go up, so the car is basically undrivable. Throwing random parts at a problem is the most expensive way to diagnose the cause of it. Way too often people ask for help after wasting a lot of money and time when it would have been less expensive to take the car to a mechanic. I'd feel a lot better if you'd wait for KRAKENAUTO to return and help you diagnose this.
We may need to ask you to start a new question since this is a different problem. There's two reasons for this. First, these get categorized by model and by symptom to make it easier for others researching a similar problem to find your solution without having to type their own question. When a second problem gets addressed, it won't show up on any list and won't be of help to others.
Second, unlike on other forums where anyone can chime in and confuse the issue, here it becomes a private conversation between you and your expert. Only the two of you will get automated e-mails directing you back here when any reply is posted. As such, none of the other experts will see the new question or have a chance to reply. That may not get you the best help. Most of us have areas we specialize in, and we look for questions with those topics. KRAKENAUTO is the better choice for electronic throttle body topics, but one of the other experts might reply first if he feels competent in that area.
If needed, here's the link to start a new question:
https://www.2carpros.com/questions/new
In the meantime, I CAN add a couple more comments while we're waiting. First, be aware with any diagnostic fault code, there is always a long list of requirements that must be met for a code to set. One requirement is certain other codes can't already be set, and sometimes those other codes don't appear to be related. For example, the Engine Computer knows after the engine has been off at least six hours, the coolant temperature sensor and the intake air temperature sensor had better be reading the same temperature. If they are not, it has strategies to figure out which one is wrong. If there's a failure in one of those circuits, a fault code is set, but then the computer knows it can't rely on its readings, so it suspends some of the tests on the second sensor. If a problem develops with that second circuit, it will go undetected until the first problem is repaired, then the tests on the second sensor resume. This is where we hear stories about someone having the problem repaired, then the Check Engine light turns right back on when they leave the repair shop. No one, including the mechanic, had any idea there was a second problem until the computer resumed testing it and detected the problem. This happens much more often when the first problem is ignored for a long time. That gives more time for the second problem to develop.
Next, as part of that long list of requirements, a defect might have to be detected at least two times on two different drive cycles before the code sets, or it may have to occur for a specified period of time. In the case of electronic throttle body systems, there's two throttle position sensors on the accelerator pedal, and two more on the throttle body assembly. Some systems will run when just one of those four fails, but the warning light will turn on. There has to be a fault code, but you might not find it with a code reader. A scanner will look in all the computer modules to find that code.
Be aware too, the arrow warning light might just mean the electronic throttle body system is shut down or has limited function as a result of some other problem, not a problem with the throttle body system itself. Other than the electronics part of it, system operation is not an area of my expertise, and it varies among manufacturers and models. Throttle response could be limited as a result of a transmission electrical or mechanical problem. They might do that because way too often owners don't understand that when in limp mode, (stuck in second gear), they can't go normal highway speed. Limp mode is designed to allow you to drive to a repair shop slowly without needing a tow truck. Driving at highway speed for a long time will damage the engine. I could even imagine an electronic throttle body system forcing reduced engine speed when a tire with very low pressure is detected.
When you start the discussion on the transmission in limp mode, there's an important observation you can make to speed it up. That is to see when it goes into that mode. If you start the engine, shift out of "park", into "drive", and it immediately goes to second gear and stays there, it is most likely an electrical issue. That gets detected right away. On the other hand, if it starts out in first gear, like normal, up-shifts normally to second gear, and perhaps the higher gears, then suddenly bangs back down to second gear, it is more likely a mechanical problem inside the transmission. Excessive clutch plate slippage in one of the clutch packs, especially at the mileage you listed, is the better suspect. Worn clutch plates and leaking rubber lip seals are the more typical causes of slipping clutch packs. That type of problem commonly only acts up once in a while at first, but will become more frequent over more miles.
I'm quite pleased you solved the first problem with nothing more than a new sensor. I'll be waiting to see how this new problem plays out. Hopefully it won't be expensive.
Wednesday, December 17th, 2025 AT 2:34 PM
