P2112 code definition
Throttle Actuator Control System - Stuck Closed
What the P2112 code means
P2112 is a general ODB2 diagnostic trouble code indicating a fault with the throttle actuator control system. This code may be seen with other throttle body codes.
The P2112 code tells us that the throttle body actuator control system has found a stuck closed throttle plate. When the throttle plate is stuck closed, it will not allow air into the intake manifold system. The Engine Control Unit (ECU) detects the throttle plate actuator stuck closed and triggers a Check Engine Light to be set on the dashboard. In addition to the Check Engine Light, the ECU sets a failsafe mode for all engine settings that will remain until the fault is resolved or the code is repaired.
What causes the P2112 code?
Multiple different components can cause the P2112 code such as:
- Open or short in the wiring harness for the throttle actuator
- Failed throttle actuator
- Throttle plate stuck closed
- Poor throttle actuator electrical connection
- Throttle position sensor failed or faulty readings.
What are the symptoms of the P2112 code?
Common symptoms are:
- Check Engine Light displayed on the dashboard
- Engine may have severely reduced or no power
- Stalling engine
- Engine may not start and run at all
- Misfire condition
How does a mechanic diagnose the P2112 code?
The first thing a mechanic will do is hook up a scan tool and check for any codes present.
Once all codes are found, including history and pending codes, they will be noted as well as the freeze frame data that is associated with each code.
Then, all the codes will be cleared for a clean slate. With the codes cleared, a test drive will be attempted in cases where a test drive is possible. The test drive should be as close to the conditions in the freeze frame from the original code as possible.
Next, the scan tool will be used to check the throttle position sensor data in the datastream.
Then, a visual inspection will be performed looking for any damaged wiring, sensors or throttle linkage. The throttle body should be inspected which will require the removal of the air intake tube. With the air intake tube off, the technician will look for any carbon deposits sticking the throttle plate closed, and attempt to manually operate the throttle plate.
Lastly, the scan tool is used to monitor the throttle postion sensor readings and that they change when the throttle is operated.
Common mistakes when diagnosing the P2112 code
Common mistakes include replacing the throttle body actuator when it is either stuck closed with carbon, or the throttle body position sensor is reading improperly. Failure to follow diagnostic steps can lead to mistakes and improper diagnosis in most cases.
How serious is the P2112 code?
The seriousness of the P2112 code will vary greatly depending on the symptoms. If the throttle body is stuck closed, commonly the vehicle will stall and die, or just not run at all. In cases where the wiring or throttle position sensor are faulty, then the vehicle may run, but suffer from misfires and run poorly.
What repairs can fix the P2112 code?
- Repairing or replacing wiring harness as needed
- Replacing faulty throttle position sensor
- Replacing throttle body actuator
- Fixing a poor electrical connection point
- Unsticking the throttle body plate
Additional comments for consideration regarding the P2112 code
When the throttle body plate is stuck, it can be for a number of reasons such as carbon buildup or age. As vehicles go up in mileage and over 100k, they can get excessive carbon buildup around the throttle body plate. This can allow the throttle to not open or close properly, or become stuck open or closed. Throttle body cleaners can be used sparingly to clean the carbon buildup and restore proper throttle plate function.
To properly diagnose the P2112 code, an advanced level scan tool will be needed. This type of scan tool allows technicians to view live engine data that is otherwise unable to to be accessed. Normal scan tools will only allow the code to be viewed and cleared and in some cases, the freeze frame data can be viewed.
Need help with a P2112 code?
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.