P2112 on 2013-2016 Mazda CX-5: Throttle Stuck Closed Causes and Fixes

What's Unique About the 2013-2016 Mazda CX-5

For many Mazda vehicles with Skyactiv engines, including the CX-5, the P2112 code has a very specific and common cause that is not a simple part failure: throttle body icing. In freezing temperatures, condensation from the PCV system can freeze the throttle plate shut overnight. Mazda has addressed this on similar models like the CX-9 with a PCM software update that cycles the throttle valve after shutdown to prevent ice formation. While a specific TSB for the 2013-2016 CX-5 isn't widely cited, TSB 01-013/16 addresses PCM updates for throttle control logic, and the shared technology and owner experiences make this the number one suspect if the code appears in cold weather.

Symptoms You May Notice

• Check Engine Light is on
• Electronic Throttle Control (wrench) light is on
• Vehicle enters 'limp mode' with drastically reduced power
• Sluggish or no acceleration
• Poor throttle response
• Engine may stall or have a rough idle
• Vehicle may not start

Most Likely Causes

1. Throttle Body Icing (in Freezing Temperatures) 🔴 High Probability → Shop Fuel Injection Throttle Body Condensed moisture from the PCV system freezes the throttle plate shut. Mazda acknowledged this on similar platforms with a software fix.
   How to confirm: The issue occurs only on cold starts in below-freezing weather. The code may disappear after the engine warms up and thaws the ice. Freeze frame data may show a low intake air temperature at the time of the fault.
   Typical fix: A Powertrain Control Module (PCM) software update from a Mazda dealership. The updated software cycles the throttle valve after engine shutdown to prevent ice formation. This may be covered under the federal emissions warranty (8 years/80,000 miles). Check with a dealer about TSB 01-013/16 or similar software updates.
   Est. part cost: $0 - $150
2. Dirty or Carbon-Clogged Throttle Body 🟡 Medium Probability → Shop Fuel Injection Throttle Body Direct injection engines like the Skyactiv-G can contribute to carbon buildup in the intake tract over time, restricting the movement of the throttle plate.
   How to confirm: Visually inspect the throttle body bore and plate for black carbon deposits that could cause sticking. The throttle may feel sticky or sluggish if moved by hand (with ignition off).
   Typical fix: Remove the air intake hose and clean the throttle body and plate thoroughly with a dedicated throttle body cleaner and a soft cloth or brush. 🎬 Watch: How to clean a Skyactiv throttle body A throttle relearn procedure is recommended afterward.
   Est. part cost: $5 - $15
3. Failed Throttle Body Assembly ⚪ Low Probability → Shop Fuel Injection Throttle Body
   How to confirm: After cleaning the throttle body and verifying the software is up to date, the code returns. This points to a failure of the internal throttle actuator motor or position sensor. You may hear a whining or grinding from the throttle body area.
   Typical fix: Replace the entire throttle body assembly.
   Est. part cost: $200 - $500

Rare But Worth Checking

• Wiring Harness or Connector Issue: Check for damage to the wiring leading to the throttle body, especially if any other work has been done in the engine bay. A visual inspection for frayed wires or corroded connector pins is a quick and important step.
• Powertrain Control Module (PCM) Failure: This is extremely rare. The PCM should only be considered as the cause after all other possibilities, including wiring, have been exhaustively ruled out by a professional.

Diagnosis Steps

1. Scan the vehicle for codes. Confirm P2112 is present and note any other codes.
2. Consider the weather conditions. If the code appeared in freezing temperatures, the primary suspect is throttle body icing. Contact a Mazda dealer to check for available PCM software updates, referencing TSB 01-013/16.
3. If weather is not a factor, inspect the throttle body. Remove the intake boot and visually check for heavy carbon buildup around the throttle plate and bore.
4. If dirty, clean the throttle body using a dedicated throttle body cleaner and a soft rag. Do not spray excessively and avoid getting solvent into the electronic components.
5. After cleaning, perform a throttle body relearn procedure. A common method is to disconnect the battery for 5 minutes, reconnect it, turn the ignition ON (engine off) for one minute, then OFF for one minute. Finally, start the engine and let it idle without any electrical load until it reaches operating temperature.
🎬 See: Four ways to perform a throttle relearn
6. If the code persists after cleaning, inspect the throttle body connector and wiring harness for any signs of damage, corrosion, or loose connections.
7. If wiring is intact and the problem continues, the throttle body assembly itself has likely failed and requires replacement.
🎬 Watch: Quick and easy throttle body replacement guide

Parts You'll Likely Need

• Throttle Body Assembly (2.5L) (OEM #PY01-13-640A) — This part is needed if cleaning the original unit and updating the PCM software does not resolve the code, indicating a failure of the internal motor or sensor. This is for the 2.5L engine.
  Trusted brands: Mazda (OEM), Hitachi
  OEM price range: $400-$500
  Aftermarket price range: $200-$350
• Throttle Body Assembly (2.0L) (OEM #PE01-13-640) — This part is needed if cleaning and software updates fail on a vehicle with the 2.0L engine.
  Trusted brands: Mazda (OEM), Hitachi
  OEM price range: $400-$500
  Aftermarket price range: $200-$350
• Throttle Body Cleaner — This is the first-line solution for fixing a P2112 code caused by carbon buildup.
  Trusted brands: CRC, WD-40
  Aftermarket price range: $5-$15

Related Codes That Often Appear With This One

• P2101 — This code indicates a performance problem with the throttle actuator control motor circuit itself. It often appears with P2112 as it points directly to a problem with the motor that controls the throttle plate.

Technical Service Bulletins (TSBs) & Recalls

• TSB #01-001-18-3419a / #01-001-20-3650: While officially for the Mazda CX-9, these bulletins describe the throttle body freezing issue and the software update fix, which is highly relevant to the CX-5 with the same engine technology. Manufacturer TSB Bulletin #01-001-20-3650 specifically notes that when operating the vehicle in temperatures below freezing, customers may experience a lack of power with the check engine light on and DTC P2112:00 stored in memory.
• TSB #01-013/16: This TSB for the CX-5 involves a PCM software update to improve engine control logic, which may include the fix for throttle body icing.
• TSB Bulletin #01-001-18-3419a: This bulletin similarly describes the throttle valve actuator control range/performance problem occurring at temperatures below freezing, leading to a lack of power.

Platform-Specific Known Issues

• A known issue on Mazda Skyactiv platforms involves the throttle body freezing in cold climates, which is often resolved with a PCM software update from a dealer.

Mechanic-Grade Diagnostic Values

• Throttle Position Sensor (TPS) Voltage — expected: Approx. 0.5V - 0.7V at closed throttle, increasing smoothly to approx. 4.5V at wide-open throttle.. Failure: Voltage is erratic, does not change smoothly, or is outside the expected range.
• Throttle Actuator Motor Resistance — expected: A specific ohm range between the two motor terminals (E and F). While the exact value for this Mazda isn't listed in public sources, a typical range is 1-10 ohms.. Failure: An open circuit (infinite resistance) or a short (zero resistance) indicates a failed motor.
• Commanded vs. Actual Throttle Angle (Live Scan Data) — expected: The actual throttle position should closely mirror the commanded position as the accelerator is pressed.. Failure: A discrepancy of more than 6-10% between the commanded and actual angle will trigger the fault code.
• Throttle Actuator Supply Voltage (Key On, Engine Off) — expected: Battery voltage (approx. 12V) at the power supply pin in the throttle body connector.. Failure: Low or no voltage points to a wiring, fuse, or PCM power supply issue.

Scan Tool Commands That Help

• Mazda IDS (or equivalent professional scanner): Active Test / Bidirectional Control for Throttle Actuator — This function allows a technician to command the throttle plate to open and close directly from the scan tool. It is used to verify if the actuator motor is physically capable of moving, bypassing the accelerator pedal input. If the plate moves with the scan tool but not the pedal, the issue may be in the pedal sensor or its circuit. If it fails to move, it confirms a problem with the throttle body, wiring, or PCM driver.
• Mazda IDS (or equivalent professional scanner): Throttle Body Relearn / Reset — This function should be performed after cleaning or replacing the throttle body. It resets the stored learned values for the closed and open positions, ensuring the PCM has an accurate baseline for throttle control.

Wiring & Ground Locations

• G03 — Located on the left front of the engine compartment.. This is a primary engine compartment ground point. A loose or corroded connection here can cause erratic voltage and unpredictable behavior in various engine sensors and actuators, including the electronic throttle body.
• G09 — Located behind the instrument cluster.. This is a key interior ground point for many control modules. While less likely to be the primary cause, a fault here could disrupt communication or power to the PCM or related interior modules, indirectly affecting throttle control.
• Throttle Body Connector — A 6-pin connector directly on the electronic throttle body assembly, attached to the intake manifold.. This is the single point of failure for all power, ground, and signal wires to the throttle body. Technicians must check for continuity between the throttle body connector terminals and the corresponding PCM terminals (e.g., Terminal F to PCM 2A, Terminal E to PCM 2B) to rule out a wiring harness break.

Real Owner Repair Stories

• Mazda Forum (mazda-forum.com) (2015 Mazda CX-5) — Minor vibration at idle.
  ❌ Tried (didn't work) Initial incorrect relearn procedure.
  ✅ What actually fixed it The user performed a throttle body cleaning. The forum then provided a successful manual relearn procedure: Disconnect the battery for 5 minutes, reconnect, start the engine with all accessories off, and let it idle for 5 minutes before driving normally. This resolved the post-cleaning idle issue.

OEM Part Supersession History

• PY01-13-640 → PY01-13-640A — Part revision or manufacturer change. This is a common practice to address minor issues or switch suppliers.
  Heads up: The parts are interchangeable, with PY01-13-640A being the current replacement for the 2.5L engine.
• PE01-13-640 → PE01-13-640B — Part revision or manufacturer change.
  Heads up: PE01-13-640B is the updated part for the 2.0L engine. It is not interchangeable with the 2.5L (PY01) part.

Model Year Variations Within This Range

• 2016: The Mazda CX-5 received a facelift for the 2016 model year. While the core engines and throttle body part numbers (PE01 for 2.0L, PY01 for 2.5L) remained the same as prior years, there could be subtle differences in wiring or PCM software versions. It's important to ensure any software updates (like the one for throttle icing) are correct for the specific model year.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• LED Daytime Running Light (DRL) Failure 🟠 Medium — Very common on 2016 models, but also reported on others. The LED strip flickers or fails completely. (Ref: Safety Recall 4320A for 2016 models. The gasket material can release sulfur, corroding the LED circuit.)
• Infotainment 'Ghost Touch' and Malfunctions 🟡 Low — Common across this generation. The screen registers phantom touches, causing random menu changes or calls. Often happens when the vehicle is stopped. (Ref: A TSB (SSPB6) was issued for the Mazda3 but the issue is widespread on the CX-5 as well. The common DIY fix is to disconnect the touchscreen's ribbon cable, forcing reliance on the commander knob.)
• Cracked Cylinder Head (2.5T Engine) 🔴 High — While more documented on the turbocharged 2.5L engine in the CX-9, the underlying engine architecture has similarities. It's a known, serious issue where a casting defect can cause a coolant leak behind the exhaust manifold. (Ref: TSB 01-013/21 applies to the 2.5T engine but highlights a potential manufacturing weakness in the Skyactiv family.)
• Premature Rear Brake Wear / Sticking Calipers 🟠 Medium — Reported by many owners, leading to rapid pad and rotor wear.
• Easily Cracked Windshield 🟡 Low — Numerous owner complaints suggest the factory windshield is prone to cracking from minor impacts or even temperature changes.
• Shifter Park Sensor Failure 🟡 Low — A faulty switch in the shifter assembly can prevent the car from recognizing it's in Park, leaving accessories on and draining the battery.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used throttle body from a reputable auto recycler is a reasonable choice for this repair, especially if the failure is a confirmed internal electronic or motor fault. Since the most common causes are icing (software) and carbon buildup (cleaning), a used part should only be considered after these have been ruled out. A used part offers significant cost savings over a new OEM unit.

Donor-vehicle mileage cap: roughly under 80000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the part number on the used unit (PY01 for 2.5L, PE01 for 2.0L) matches your original exactly.
• Inspect the throttle plate and bore for excessive scoring or damage, though some carbon is expected.
• Ensure the electrical connector pins are straight and free of corrosion.
• Ask the recycler for the VIN or mileage of the donor vehicle if possible.
• Prefer parts from vehicles with rear-end collision damage over front-end, as this reduces the likelihood of impact damage to engine components.

OEM-only on this vehicle (don't cheap out):

• While the throttle body itself can be sourced from aftermarket or used, if the problem is diagnosed as a PCM failure, it is highly recommended to use an OEM Mazda PCM programmed by a dealer or specialist.

Aftermarket brands forum-validated for this vehicle:

• Hitachi (Often the Original Equipment Manufacturer)
• Beck/Arnley
• Spectra Premium

Brands owners have reported issues with on this vehicle:

• Unbranded, ultra-low-cost units from online marketplaces can have a high failure rate due to inferior internal electronics and motors. It is better to buy a used OEM part than a questionable new one.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P2101 — Often related to throttle actuator control motor circuit range/performance issues, which can occur alongside P2112 if the motor fails or is obstructed by ice/carbon.
• P0507 — Idle control system RPM higher than expected; often occurs after cleaning the throttle body if a throttle relearn procedure is not performed.
• P0113 — Intake Air Temperature sensor circuit high; freeze frame data for P2112 often shows low intake temperatures which helps confirm the icing theory.

Frequently Asked Questions