P2112
Throttle Actuator Control System - Stuck Closed
If your code reader dashboard displays the generic DTC error code P2112, your vehicle is currently experiencing an active failure related to "Throttle Actuator Control System - Stuck Closed". Proper system troubleshooting is required to safely clear this warning.
Driver's Summary
Code P2112 means your vehicle detected a problem with the throttle actuator control system - stuck closed system. On the road, this usually shows up as engine cranks but won't start, or starts and stalls immediately. This is a serious fault — avoid extended driving and have your vehicle inspected by a mechanic as soon as possible to prevent further damage.
Symptoms
Engine cranks but won't start, or starts and stalls immediately
Common Causes
- Carbon coking sealing the throttle plate shut
- Ice buildup in throttle body (cold climates)
- Failed throttle body motor
- Damaged throttle plate
How to Fix
- 1 Manually clean the throttle body
- 2 Allow vehicle to thaw in a warm garage
- 3 Replace the electronic throttle body
- 4 Check air filter box for debris
Technical Explanation
The PCM triggers P2112 after its internal monitoring routine detects that a specific circuit or sensor has exceeded its acceptable operating range. The control module samples the circuit continuously during normal operation, using both voltage level monitoring and frequency analysis to detect open circuits, shorts to ground, shorts to battery voltage, and high-resistance connections. After two failed drive cycles, the code transitions from a pending to a confirmed DTC, and the PCM activates the MIL. Clearing the code without repairing the fault will result in re-illumination within one to two complete drive cycles.
Is It Safe to Drive?
With P2112 active, your engine or transmission is not operating within design parameters. Short-term driving may seem fine, but internal damage is accumulating — particularly to carbon coking sealing the throttle plate shut.
Mechanic's Pro Tip
When diagnosing P2112, start with the cheapest and most accessible potential causes first: verify fuses, relay operation, and connector integrity before purchasing any parts. Use a scan tool to capture live data during the fault condition — static readings with the fault absent often yield no useful information. Document the freeze frame data stored with the code; it records the exact engine conditions (RPM, load, coolant temp, fuel trim) at the moment the fault was detected and is invaluable for replicating the fault on a test drive.
Throttle body clean: $80; Throttle body replacement: $300 - $600