P2112 Code: Throttle Actuator Control System – Stuck Closed
The PCM asked the throttle to open, but it stayed shut – the engine can't get air, so it bogs or stalls.
At a glance
Severity: High
- Meaning
- Throttle Actuator Control System – Stuck Closed
- System
- Speed & Idle Control · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $10–$950
- DIY difficulty
- Moderate
P2112 is the mirror image of P2111: the PCM commands the throttle plate to open, but the position sensors say it hasn't moved off its closed position. Without air the engine can only idle poorly, stumbles when you press the pedal and often dies. The classic case is a cold, humid morning after a car wash or a night of freezing drizzle, when a film of ice locks the plate to the bore; the code then goes away once the engine bay warms up. Carbon that glues the plate shut after the car has been parked for a while, stripped plastic gears or a seized motor are the other big causes. Unlike a stuck-open throttle, this failure takes power away rather than adding it, but losing power in traffic is still a hazard.
Can I keep driving? Don't set off until the engine responds normally to the pedal. If the code set on a frosty morning, let the car warm up at idle or thaw indoors and recheck; if it returns in mild weather, have the throttle body checked before relying on the car in traffic.
How to read P2112
- P Powertrain
- 2 Generic (SAE)
- 1 Fuel & air metering
- 12 Specific fault
Symptoms
- Engine starts but won't rev when you press the pedal
- Low, shaky idle that may die within seconds
- Stalling as soon as you pull away or shift into gear
- Problem on cold, damp mornings that disappears once warm
- No power at all, even in reduced-power mode
- Check engine light, often with an electronic throttle warning
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Ice locking the plate to the bore in freezing, humid conditions
- Carbon and gum gluing the plate at the closed stop, typically after standing
- Stripped reduction gears or a seized throttle motor
- Open or high-resistance motor circuit so the motor can't drive the plate
- Position sensor reporting 'closed' although the plate moves
- PCM driver fault
Diagnosis step by step
Check ambient conditions in the freeze frame
Look at intake air temperature and coolant temperature when the code set. Readings near or below 32 °F on a cold start make ice the prime suspect; codes set on a warm engine point toward a mechanical or electrical failure.
Tools: OBD-II scanner
Watch the plate during the key-on sweep
With the intake duct removed and hands well clear, have a helper switch the ignition on and slowly press the pedal (engine off). On most systems the plate should open visibly; if it stays shut while commanded throttle rises in live data, the plate, gears or motor are the problem.
Tools: OBD-II scanner, Flashlight
Check for ice or glue at the closed stop
Key out, try easing the plate open with a gloved finger. If it is stuck, don't force it; let the car thaw or soften carbon with cleaner on a rag, then check whether it moves smoothly afterward.
Tools: Gloves, Soft brush
Check the throttle body heater circuit
Many throttle bodies are warmed by coolant hoses to prevent icing. Make sure both hoses get warm as the engine heats up; a blocked or air-locked heater circuit lets ice form again every cold night.
Tools: Flashlight
Measure the motor and its supply
Measure motor winding resistance at the throttle body and check both motor wires back to the PCM. A good motor that won't turn the plate suggests stripped gears; an open or high-resistance motor points to the throttle body or its circuit.
Tools: Multimeter
Replace, relearn and test in the cold
If the plate, gears or motor are at fault, replace the throttle body and relearn it. Where icing was the cause, confirm the heater circuit and PCV system are working, then recheck on the next cold start.
Tools: OBD-II scanner
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Thaw and clean throttle body, relearn | Yes | $10–$150 |
| Repair throttle body coolant heater hoses or bleed air | No | $60–$250 |
| Repair throttle motor wiring | No | $100–$350 |
| Replace electronic throttle body and relearn | No | $350–$950 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Field data
| Ford | 258 | ||
|---|---|---|---|
| Dodge | 2 | Avenger, Journey |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P2112 lights the check engine light, so an OBD emissions or smog test fails. If ice was a one-off cause, clear the code and drive several trips so the monitors complete before retesting.
Frequently asked questions
The car was fine once it warmed up – do I need a repair?
If the code set once on a freezing morning after a wash, ice is the likely cause and no parts may be needed. If it keeps coming back, check the throttle body heater hoses and the PCV system, which supply the moisture and warmth that decide whether icing happens.
Can I pour hot water on a frozen throttle body?
It's better not to. Hot water can crack plastic housings and get into the motor and connector, and the melt can freeze again. Let the car warm up at idle or thaw it indoors instead.
How is P2112 different from P2111?
P2111 means the throttle stays more open than commanded, which risks unwanted engine speed. P2112 means it won't open, so the engine lacks air and stalls. The causes overlap – ice and carbon – but the safety picture is different.