What is P2112?
P2112 is a generic OBD-II diagnostic trouble code that indicates the throttle actuator control system is stuck in the closed position. This code applies to vehicles with electronic throttle control (drive-by-wire) systems.
In our workshop, we've encountered the P2112 throttle actuator control system fault code across various car makes, but it seems to be more prevalent in certain European vehicles. For example, we recently had a Volvo XC60 come in with reduced engine power and poor acceleration. After scanning the codes, we found P2112 as the culprit. We've seen similar issues in other Volvos, as well as some Volkswagen and Audi models. While not as common, we've also dealt with P2112 in a handful of Ford and Dodge vehicles. Based on our experience and research on automotive forums, it appears that this fault code is more likely to occur in drive-by-wire throttle systems, which are becoming increasingly common in modern vehicles across all makes.
Severity and Driving with P2112
Severity: The P2112 code is considered severe as it can cause significant drivability issues and potential safety concerns. When this code is triggered, the vehicle will likely enter a "limp home" mode with reduced engine power.
Driving with P2112: It is not recommended to continue driving a vehicle with an active P2112 code. The stuck throttle can lead to poor acceleration, rough idling, stalling, and an inability to properly control the vehicle's speed. If the code appears, it's best to have the vehicle towed to a repair shop to diagnose and fix the issue.
Parts Involved
The main components related to the P2112 code are:
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Throttle Body: Houses the throttle plate that controls the amount of air entering the engine. In drive-by-wire systems, the throttle body is electronically controlled.
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Throttle Actuator Motor: Receives signals from the engine control module (ECM) to adjust the throttle plate position based on driver input and engine conditions.
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Throttle Position Sensor (TPS): Monitors the position of the throttle plate and sends feedback to the ECM.
Common Causes
- Faulty throttle body or actuator motor
- Damaged or corroded wiring and connectors
- Carbon buildup on the throttle plate causing it to stick
- Malfunctioning throttle position sensor
- Issues with the ECM
Diagnosing P2112
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Scan for codes: Use an OBD-II scanner to verify the presence of P2112 and check for other related codes.
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Visual inspection: Check the throttle body, wiring, and connectors for visible damage, corrosion, or obstruction.
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Test throttle position sensor: Use a multimeter to test the TPS for proper operation according to the vehicle's service manual.
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Check for vacuum leaks: Inspect the intake system for vacuum leaks that could affect the throttle actuator control system.
Solutions
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Clean the throttle body: If carbon buildup is causing the throttle plate to stick, cleaning the throttle body with a dedicated cleaner may resolve the issue.
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Replace the throttle body: If cleaning doesn't work or the throttle body is damaged, replacement is necessary. Ensure the correct part is used for the specific vehicle make and model.
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Repair wiring: If wiring or connectors are damaged, repair or replace them as needed.
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Replace throttle position sensor: If the TPS is faulty, replace it with a new unit.
Prevention
- Regular maintenance, including air filter replacement and fuel system cleaning
- Addressing any vacuum leaks promptly
- Avoiding aftermarket modifications that could affect the throttle control system
Cost of Repair
- Throttle body cleaning: $50-$150 USD (€45-€135 EUR)
- Throttle body replacement: $200-$750 USD (€180-€675 EUR)
- Throttle position sensor replacement: $100-$300 USD (€90-€270 EUR)
- Wiring repairs: $50-$200 USD (€45-€180 EUR)
Note: Prices may vary depending on the vehicle make, model, and location.
Related Fault Codes
Other throttle actuator control system fault codes that may appear alongside P2112 include:
- P2111: Throttle actuator control system – stuck open
- P2101: Throttle actuator control motor circuit range/performance
- P2135: Throttle/pedal position sensor/switch A/B voltage correlation
Frequently Asked Questions About the P2112 Fault Code
What does the P2112 code mean?
The P2112 is a generic OBD-II diagnostic trouble code that indicates the throttle actuator control system is stuck in the closed position. This code applies to vehicles with electronic throttle control (drive-by-wire) systems.
How serious is the P2112 code?
The P2112 code is considered a severe issue as it can cause significant drivability problems and potential safety concerns. When triggered, the vehicle will likely enter a “limp home” mode with reduced engine power.
Is it safe to drive with a P2112 code?
No, it is not recommended to continue driving a vehicle with an active P2112 code. The stuck throttle can lead to poor acceleration, rough idling, stalling, and an inability to properly control the vehicle’s speed. If the code appears, have the vehicle towed to a repair shop for diagnosis and repair.
What are the common symptoms of a P2112 code?
Common symptoms include reduced engine power, poor acceleration, engine idling issues, and the engine entering a fail-safe or limp mode.
What causes a P2112 code?
Possible causes of a P2112 code include a faulty throttle body or actuator motor, damaged wiring and connectors, carbon buildup on the throttle plate causing it to stick, a malfunctioning throttle position sensor, or issues with the powertrain control module (PCM).
How do you diagnose a P2112 code?
To diagnose a P2112 code:
- Scan for codes with an OBD-II scanner to confirm P2112 and check for other related codes.
- Visually inspect the throttle body, wiring, and connectors for damage, corrosion, or obstruction.
- Test the throttle position sensor using a multimeter.
- Check for vacuum leaks in the intake system.
Can a P2112 code be caused by a vacuum leak?
Yes, a vacuum leak in the intake system can cause issues with the throttle actuator control system and trigger a P2112 code.
How do you fix a P2112 code?
Fixes for a P2112 code include:
- Cleaning the throttle body if carbon buildup is causing the throttle plate to stick.
- Replacing the throttle body if cleaning doesn’t work or it is damaged.
- Repairing damaged wiring or connectors.
- Replacing a faulty throttle position sensor.
Can cleaning the throttle body resolve a P2112 code?
Yes, if carbon buildup is causing the throttle plate to stick, cleaning the throttle body with a dedicated cleaner may resolve the P2112 code.
When should you replace the throttle body for a P2112 code?
The throttle body should be replaced if cleaning doesn’t resolve the issue or if there is visible damage to the throttle body.
What is the cost to repair a P2112 code?
The cost to repair a P2112 code can vary depending on the specific issue and vehicle, but approximate costs are:
- Throttle body cleaning: $50-$150 USD
- Throttle body replacement: $200-$750 USD
- Throttle position sensor replacement: $100-$300 USD
- Wiring repairs: $50-$200 USD
Can a P2112 code cause a no-start condition?
Yes, in some cases a P2112 code can prevent the vehicle from starting if the throttle is completely stuck closed and unable to allow air into the engine.
Is a P2112 code specific to certain vehicle makes?
No, P2112 is a generic code that can apply to any vehicle with an electronic throttle control system, including vehicles from Ford, GM, Chrysler, Toyota, Honda, and more.
Can a faulty PCM cause a P2112 code?
Yes, while less common than other causes, a malfunctioning or failing powertrain control module (PCM) can trigger a P2112 code.
What other codes may appear with P2112?
Related throttle actuator control system codes that may appear with P2112 include P2111 (stuck open), P2101 (control motor circuit range/performance), and P2135 (throttle/pedal position sensor correlation).
Can a P2112 code trigger the check engine light?
Yes, when the P2112 code is detected, it will illuminate the check engine light on the vehicle’s dashboard.
How can you prevent a P2112 code from occurring?
To help prevent a P2112 code, perform regular maintenance including air filter replacement and fuel system cleaning, address any vacuum leaks promptly, and avoid aftermarket modifications that could affect the throttle control system.
Is a throttle body relearn procedure necessary after fixing a P2112 code?
Some vehicles may require a throttle body relearn procedure after replacing the throttle body to resolve a P2112 code. Consult the vehicle’s service manual for specific instructions.
What tools are needed to diagnose a P2112 code?
To properly diagnose a P2112 code, you will need an OBD-II scanner capable of reading generic and manufacturer-specific codes, a digital multimeter for testing electrical components, and a vacuum gauge for checking the intake system for leaks.
Can a P2112 code return after being repaired?
Yes, if the underlying cause of the P2112 code is not properly addressed, or if there are additional faults in the throttle actuator control system, the code may reappear after being cleared. Thorough diagnosis and repair are crucial to preventing the code from returning.