Our certified mechanics come to you · Get a fair and transparent estimate upfront
P2111 is a diagnostic trouble code (DTC) for "Throttle Actuator Control System - Stuck Open". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
Throttle Actuator Control System - Stuck Open
In this case the code definition is fairly self explanatory. The throttle is stuck open. It’s important to understand that the PCM (Powertrain Control Module) uses a sensor to monitor the position of the throttle plate. The throttle plate may actually be working correctly but the sensor may have failed and would be reporting the incorrect position to the PCM.
This code is set when the PCM sees the throttle plate sticking in an open position. Usually this is due to a faulty TPS (Throttle Position Sensor). If this code is set and the throttle plate is actually stuck open, there will be other codes set and the TPS may actually be relaying the correct information to the computer.
If the throttle plate is actually stuck open, most likely the PCM will put the vehicle in an engine shutdown mode. If the PCM allows the motor to continue to run with the throttle plate open, the motor will idle excessively high making it unsafe to drive and possibly causing engine damage.
The most likely symptom will be the car will drive normally with the Check Engine Light on or the vehicle will go into an engine shutdown mode for safety reasons.
To begin, the technician should confirm the throttle plate is actually stuck open. If the throttle plate moves when the gas pedal moves, the next thing to check is the signal from the TPS to the computer.
This is done by watching scan data as the throttle pedal is depressed. If the TPS data on the scanner does not react to throttle pedal input, a pinpoint test should be performed at the TPS. A pinpoint test requires a multimeter to directly test the resistance value and or voltages at the TPS. Each manufacturer will have a different design for these systems therefore the specific test procedures will vary.
On the other hand, if the throttle plate does not move when the gas pedal is depressed and released, and the throttle plate is actually not moving, the scanner should again be used to check all other data that is used by the PCM to calculate throttle plate position. The majority of the time, there will be other codes set if this condition exists.
The diagnosis of this system can be confusing. Each manufacturer will have a different strategy for managing the throttle system. It’s important to take the time to study the system being worked on.
It is common for a mechanic to replace one or more components based on a single code. This could be a mistake if all codes and data aren’t closely considered. As an example, if the throttle pedal position sensor is not working, the PCM won’t know the driver is pushing on the gas pedal. If the technician misses this fact and assumes the throttle valve is simply stuck, he or she might replace the throttle body assuming it is the problem when the actual problem is the throttle valve not moving because the PCM isn’t receiving input from the throttle pedal sensor.
This code is serious in that it is a safety feature for both the engine and the occupants of the vehicle. Most likely the vehicle will fall into a default safety mode that won’t allow the engine to start. A stuck open throttle plate can lead to accidents and or engine damage. If this code is present, it’s keeping you safe.
Replace the TPS. Commonly this will require the throttle body to be replaced as the TPS and the throttle body is an integrated unit.
Clean the throttle body. A buildup of carbon around the throttle plate can lead to sticking. The throttle plate should be cleaned with every tuneup.
Replace the throttle body. Again, the throttle body is usually an all inclusive unit on electrically controlled throttles. The throttle body consists of the TPS, throttle valve (aka throttle plate) and throttle valve motor.
Replacing the PCM. (Not a common failure on most vehicles)
Repair the wiring. Damage to a harness to any of the components in this system will cause problems.
Not all codes are used by every manufacturer. In my research, the only manufacturer that I found using this code is Ford. It’s important to understand the throttle plate is part of what is commonly referred to as the throttle body.
The throttle body consists of a throttle valve, throttle valve motor and TPS. Other components may be present as well, but these three are mandatory on the throttle body for an electrically controlled throttle system. Often all three components are replaced as a single unit as they are integrated components in the throttle body.
Since the throttle is not directly controlled by a traditional cable, it’s necessary to point out the PCM has total control over the throttle valve. When the gas pedal is depressed, the PCM is receiving a signal from the throttle pedal sensor informing the PCM of the driver’s wishes. The PCM will comply only if all preprogrammed parameters are met. This is a necessary safety feature to prevent vehicles from accelerating out of control.
Electrically controlled throttle systems are an effort by engineers to refine their control over modern internal combustion engines. Personally, I have mixed feelings about the advent of the electrically controlled throttle body. In my opinion, simple is better, and this system is simple in design but complicated because of the serious possibility of a failure that could lead to injury.
Most of us have heard about the problems the Toyota Prius was having. Mechanically controlled throttles have safety built into them and don’t rely on programming from foulable human beings to design safety features. Not to mention this system adds multiple components all of which are known to fail. I don’t feel the added controlled gained is worth the risk of injury, not to mention the added cost of maintenance due to the use of expensive sensors and motors required to make a system like this work.
With that said, I do personally own a vehicle with an electrically controlled throttle system. Affectionately referred to by technicians as fly by wire. My vehicle is also a Toyota. At the end of the day, I am really not to worried about my vehicle accelerating out of control as this is rare, but never the less, it is possible. I prefer the simple cable design that has been in use since the invention of the motorized carriage, aka the automobile.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.