Carbon buildup or sludge on the throttle plate and bore, preventing the plate from closing fully; Faulty throttle actuator motor or its internal windings; Throttle position sensor (TPS) signal error or intermittent connection; Wiring harness damage or corroded connectors between the throttle body and the engine control module (ECM); A binding or damaged throttle plate shaft or return spring; ECM software calibration issue or internal driver fault (less common)

DTC codes / P21xx · Fuel and air metering / P2112

P2112Throttle Actuator Control System - Unable to Close

Q: What does code P2112 mean?

Throttle Actuator Control System - Unable to Close. P2112 indicates that the engine computer commanded the electronic throttle actuator to close the throttle plate, but the throttle position sensor feedback did not show the plate moving to the expected closed position within the calibrated time. The computer detects a mismatch between the commanded throttle angle and the actual throttle angle during a close event, often setting the code when the plate sticks or the actuator fails to return.

P2112 indicates that the engine computer commanded the electronic throttle actuator to close the throttle plate, but the throttle position sensor feedback did not show the plate moving to the expected closed position within the calibrated time. The computer detects a mismatch between the commanded throttle angle and the actual throttle angle during a close event, often setting the code when the plate sticks or the actuator fails to return.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode, limiting vehicle speed
A throttle pedal that feels unresponsive or requires more pressure to accelerate
Rough idle or stalling when coming to a stop
A sudden drop in engine speed when releasing the accelerator pedal
In rare cases, the engine may hesitate or surge during light acceleration

Common causes, most likely first

Carbon buildup or sludge on the throttle plate and bore, preventing the plate from closing fully
Faulty throttle actuator motor or its internal windings
Throttle position sensor (TPS) signal error or intermittent connection
Wiring harness damage or corroded connectors between the throttle body and the engine control module (ECM)
A binding or damaged throttle plate shaft or return spring
ECM software calibration issue or internal driver fault (less common)

How to diagnose and fix it

Inspect the throttle body bore and plate for carbon deposits; clean with throttle body cleaner and a soft brush, then recheck
Check the throttle body connector and wiring for corrosion, chafing, or loose pins; repair as needed
Use a scan tool to command the throttle actuator through its full range and observe TPS feedback for smooth operation
Measure the resistance of the throttle actuator motor and compare to manufacturer specifications; replace throttle body if out of spec
Perform a throttle body adaptation or relearn procedure with a scan tool after cleaning or replacement
If the actuator and wiring test good, check for ECM software updates or known calibration issues
Replace the electronic throttle body assembly if the actuator or sensors are faulty and cannot be serviced separately

Why cleaning the throttle body often fixes P2112

Carbon buildup on the throttle plate is the most common cause of P2112, especially on engines with direct injection or high mileage, because the plate cannot seat fully closed.
A dirty throttle body may set P2112 without any driveability complaint, so technicians should not replace the actuator before inspecting and cleaning the bore.
The code can be triggered by a weak or failing battery or charging system, as low voltage during the throttle self-test can cause a false close-failure detection.
After cleaning or replacing the throttle body, a relearn or adaptation procedure is often required; skipping it can cause the code to return immediately.
A sticking throttle plate can also set companion codes like P2101 or P2135, so always check for related throttle codes before condemning the ECM.

Can I keep driving with P2112?

You can usually drive the vehicle to a repair shop, but expect reduced power and possible limp mode; avoid highway driving or situations requiring rapid acceleration until the fault is repaired.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.