Throttle position sensor

Codes related to a sensor voltage too high or too low are almost always due to a broken wire or corroded splice or connector terminal. Fault codes only indicate the circuit or system that needs further diagnosis, or the unacceptable condition. They never say to replace parts or that one is bad. It is possible for a sensor to set a voltage-high code, but it is not very common. Also, be aware you have to manually erase the code, if you did not already. Do not become confused when an old code is still there after the repairs have been completed.

You are working on a throttle-by-wire system that put Toyota in the news a few years ago. Most independent mechanics do not want to work on them for fear of becoming party to any future lawsuits. Most likely the new throttle body assembly needs to be programmed to the vehicle by the dealer. No throttle response is a very common symptom, but I have never heard of one going to wide-open-throttle related to the brakes. Seems like a pretty dangerous condition. I have a suspicion that is another symptom related to what set the fault code.

Can you get to the throttle position sensor to take some voltage readings? To be valid, they will need to be taken while it is plugged in, by back-probing next to the wires where they go into the connector.

When this type of thing happens to me, it is usually due to overlooking something I unplugged or something I broke and did not see. Using the voltmeter is typically the last step in finding the source of the problem. Before that we would use a scanner to view live data and see what the engine computer is seeing for TPS voltage. Without either of those, all you are left with is a visual inspection.