OBD-II Code P2105: Throttle Actuator Control System - Forced Engine Shutdown

What Does P2105 Mean?

P2105 means your car's main computer, the Powertrain Control Module (PCM), detected a catastrophic fault within the electronic throttle control (ETC) system. To prevent a dangerous uncontrolled acceleration scenario, the PCM commands a forced engine shutdown. This is the car's 'kill switch' activating because it no longer trusts the signals controlling engine speed.

Technical definition: The official SAE/OBD-II definition for P2105 is "Throttle Actuator Control System - Forced Engine Shutdown". This code indicates the PCM actively commanded the throttle actuator into a closed or default position, shutting down the engine. It sets because a critical, safety-related fault was detected within the electronic throttle control system or an interdependent system. P2105 is the *result* of a problem, not the root cause.

Can I Drive With P2105?

No — Do Not Drive. Driving is impossible or extremely dangerous. The vehicle's computer has executed a safety override, shutting down the engine or limiting it to zero throttle response. The vehicle will stall in traffic, fail to accelerate, or refuse to start entirely. A tow is required.

Common Causes

• Faulty or Dirty Electronic Throttle Body (Very Common) — The throttle body's internal motor fails, or the gears wear out. More commonly, heavy carbon buildup causes the throttle plate to physically stick, preventing it from closing properly. The PCM sees a mismatch between the commanded and actual position and triggers a shutdown.
• Wiring or Connector Issues (Common) — Damaged, corroded, frayed, or loose wires between the APP sensor, throttle body, and PCM interrupt critical voltage signals. Fretting corrosion on connector pins is a major issue on many GM models.
• Faulty Accelerator Pedal Position (APP) Sensor (Common) — The APP sensor houses two or three redundant sensors. If these sensors provide conflicting data to the PCM (e.g., one says 20% throttle, the other says 80%), the computer cannot trust the driver's input and shuts down the engine.
• Faulty Throttle Position Sensor (TPS) (Common) — Located on the throttle body, dual TPS sensors report the throttle plate's exact angle. If their signals are irrational, do not correlate, or don't match the APP sensor's request, the PCM declares a fault and sets P2105.
• Low or Unstable System Voltage (Less Common) — A weak battery, failing alternator, or poor ground connections provide unstable voltage to sensitive electronic modules. This causes communication errors and incorrect sensor readings, leading the PCM to trigger a false positive P2105.
• Fault in a Related System (ABS, MAF, MAP) (Rare) — Problems with the Anti-lock Brakes (ABS), Mass Airflow (MAF) sensor, or Manifold Absolute Pressure (MAP) sensor sometimes provide conflicting data to the PCM, triggering a P2105 code as a protective measure.
• Failing Ignition System Components (Rare) — Severe misfires from failing ignition coils or spark plugs cause erratic engine operation that the PCM's logic interprets as a loss of engine control, prompting a fail-safe mode.
• Software Glitch / Outdated PCM Software (Rare) — Original PCM software is sometimes overly sensitive or has logic errors leading to a false P2105 code. A technical service bulletin (TSB) often exists for a software update to correct this.
• Powertrain Control Module (PCM) Failure (Very Rare) — The car's main computer fails in very rare instances. This is the least likely cause and is only considered after exhaustively ruling out all wiring, grounds, and sensors.

Symptoms

• Engine Stalls or Will Not Start — The engine shuts off while driving and refuses to restart, or cranks but fails to fire. This is the primary symptom.
• No Throttle Response — Pressing the accelerator pedal has no effect on engine RPM. The engine idles very low or stalls immediately.
• Vehicle Stuck in 'Limp Mode' — Before a full shutdown, the car enters a severe limp mode with drastically reduced power, very slow acceleration, and a limited top speed.
• Check Engine Light is On — The Malfunction Indicator Lamp (MIL) illuminates immediately when P2105 is active.
• Multiple Warning Lights On — The Electronic Stability Control (ESC), traction control, or ABS lights illuminate simultaneously, as these systems depend on the throttle control system.
• Engine Runs Rough Briefly Before Stalling — The engine shudders or runs erratically for a moment as the PCM detects the critical fault and commands the throttle plate to close.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this code.

Common Fixes & Costs

• Clean the Electronic Throttle Body — Parts: $10-$20, Labor: $100-$200, ~1.2 hr book time (DIY)
• Repair Damaged Wiring or Replace Connector Pigtail — Parts: $30-$80, Labor: $150-$300, ~2.0 hr book time (Professional)
• Replace the Electronic Throttle Body Assembly — Parts: $150-$600, Labor: $100-$250, ~1.0 hr book time (Intermediate)
  Ford Focus/Fusion/Escape: OEM
  Chevrolet Silverado/Equinox: OEM
  Jeep Patriot/Compass: OEM
  Various: OEM
• Replace the Accelerator Pedal Position (APP) Sensor — Parts: $75-$250, Labor: $75-$175, ~0.8 hr book time (DIY)
  Ford F-150: OEM
  Chevrolet Equinox/GMC Terrain: OEM
• Update or Reprogram the PCM — Parts: $0, Labor: $100-$200, ~1.0 hr book time (Professional)

Used vs. New Parts: Buying Guide

When a used part is worth it: For older, high-mileage vehicles where the cost of a new OEM part is prohibitive. A used OEM throttle body from a low-mileage, accident-damaged vehicle is a cost-effective alternative.

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

Donor quality checklist:

• Verify the donor vehicle's mileage and ensure it was not scrapped due to engine or electrical failure.
• Visually inspect the part for corrosion, damage, and cleanliness of the throttle bore.
• Match the part number exactly, as even slight variations are incompatible.

Decision logic:

• If Vehicle is under 100K miles and a daily driver → Buy a new OEM or high-quality aftermarket part for maximum reliability and warranty.
• If Vehicle is over 150K miles and budget is the main concern → A tested, used OEM part from a reputable salvage yard is a reasonable choice.
• If The specific part has a known high failure rate (e.g., certain Ford models) → Favor a new part, preferably an updated OEM or redesigned aftermarket version (like a Dorman OE-FIX) that corrects the original flaw.

Warranty tradeoff: Used parts typically offer a 30-90 day warranty. New aftermarket parts usually come with a 1-year to limited lifetime warranty. New OEM parts carry a 1-2 year warranty.

Worst-case if a used part fails: $250-$600 if a used part fails shortly after installation, requiring repeat labor costs plus the price of another replacement part.

What Happens If You Wait — Timeline

1. First Occurrence (Intermittent): The vehicle suddenly enters limp mode or stalls, setting code P2105. After sitting, it restarts and runs normally for days or weeks. The underlying fault is temporary. (MPG impact: 0%% · Added cost: $0)
2. Weeks to Months (Increasing Frequency): Shutdown events become more frequent, occurring every few days. The driver clears the code to get home, but it returns as soon as the fault condition is met again. (MPG impact: 0%% · Added cost: $75-$300 (Potential towing cost))
3. Months (Hard Fault): The underlying problem is permanent. The code sets instantly upon startup, and the engine will not run or immediately shuts down. The vehicle is completely undrivable. (MPG impact: 100% (Vehicle is inoperable)% · Added cost: $75-$300 (Guaranteed towing cost))
4. Ignored Hard Fault: The vehicle remains disabled. Leaving the root cause unaddressed (like a wiring short) puts stress on the PCM. The primary cost is the complete loss of vehicle use. (MPG impact: 100% (Vehicle is inoperable)% · Added cost: $150-$600 (Towing plus diagnostic fees at a shop))

Cost of Not Fixing It

• Immediate: Vehicle is undrivable or extremely unsafe. The engine shuts down, potentially in traffic, requiring a tow. (Added cost: $75-$300 (for towing))
• Short-Term (if code is intermittent): Unpredictable stalling and no-start conditions pose a significant safety risk. You will be stranded without warning. (Added cost: N/A)
• Long-Term: Continued attempts to drive by clearing the code puts stress on related components, but the primary cost is the immediate lack of function and safety.

Diagnosis Steps

1. Scan for All Trouble Codes & Analyze Freeze Frame Data
   Use an advanced OBD-II scanner. P2105 is a 'result' code; you MUST find the 'cause' code (e.g., P2135, P0121). Analyze the 'Freeze Frame' data to see what sensor went out of range.
   Tools: Advanced OBD-II Scan Tool (Beginner)
2. Perform Detailed Visual Inspection of Wiring
   Thoroughly inspect all wiring harnesses and connectors to the throttle body and accelerator pedal. Look for chafing, melting, green corrosion, or pushed-out pins. Perform a 'wiggle test' with live data on screen.
   Tools: Flashlight, Inspection Mirror (Beginner)
3. Inspect the Throttle Body Plate
   Remove the air intake hose. Check for heavy carbon buildup around the throttle plate and bore. With the ignition OFF, the plate must move with firm, smooth pressure.
   Tools: Basic hand tools (Intermediate)
4. Test Sensor Voltages with Live Data or Multimeter
   Using a scan tool's live data, watch the APP and TPS sensor voltages. As you slowly press the gas pedal, APP sensor 1 sweeps smoothly (~0.5V to ~4.5V) and APP sensor 2 does the opposite, with no glitches.
   Tools: Advanced OBD-II Scan Tool, Multimeter (Intermediate)
5. Advanced Voltage Drop Test on Power and Ground Circuits
   Test for voltage drop on the throttle body and APP sensor ground circuits. With the circuit loaded (Key On, Engine Off), a reading above 100mV (0.1V) indicates high resistance. Test the power side; a drop over 200mV (0.2V) suggests a wiring issue.
   Tools: Multimeter, Vehicle-Specific Wiring Diagram (Advanced)
6. Check Power and Ground at the Throttle Motor
   Using a multimeter and wiring diagram, verify the throttle actuator motor receives the correct reference voltage (typically 5V) and has a solid ground connection (less than 0.1V).
   Tools: Multimeter, Wiring Diagram (Advanced)
7. Validate Sensor Voltage Ranges
   With the key on, engine off, check sensor voltage sweeps. Any reading outside expected ranges, or any jump/dropout, indicates a failed sensor.
   Tools: Advanced OBD-II Scan Tool, Multimeter (Advanced)
8. Analyze Sensor Waveforms with an Oscilloscope
   Graph the APP and TPS sensor outputs with an oscilloscope. Look for 'glitches' or 'dropouts' in the voltage pattern. A multimeter is too slow to catch instantaneous faults.
   Tools: Automotive Oscilloscope, Wiring Diagram (Advanced)
9. Perform a Throttle Body Relearn Procedure
   After cleaning, replacing, or unplugging the throttle body, a 'relearn' procedure is mandatory. This allows the PCM to learn the new closed, open, and resting positions of the throttle plate.
   Tools: Advanced OBD-II Scan Tool (recommended) (Advanced)

When This Code Triggers (Freeze-Frame Conditions)

• Engine Coolant Temp: 180-210°F (Fully warmed up)
• RPM: Varies (often 700-2500 RPM) (Fault can occur at idle or during steady-state cruise)
• Engine Load: 15-50% (Light to moderate acceleration or maintaining speed)
• Vehicle Speed: Varies (often 0-60 mph) (Can occur when stationary or at city/highway speeds)

Related Codes

• P2101 — 'Throttle Actuator Control Motor Circuit Range/Performance.' Indicates an electrical problem with the throttle body's motor. P2101 is a direct cause, P2105 is the effect.
• P2135 — 'Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation.' Signals from the two redundant sensors do not agree. The PCM sees this conflict and forces a shutdown.
• P2104 — 'Throttle Actuator Control System - Forced Idle.' A less severe fail-safe. The PCM detects a fault but allows the engine to run at a fixed, low idle.
• P2106 — 'Throttle Actuator Control System - Forced Limited Power.' The PCM actively limits engine power but allows some throttle response.
• P0121, P0122, P0123 — Fault with the primary Throttle Position Sensor (TPS 'A') signal being out of range. An irrational signal is a direct trigger for P2105.
• P0221, P0222, P0223 — Faults for the secondary Throttle Position Sensor (TPS 'B'). A failure from either sensor causes the PCM to lose trust and force a shutdown.

Climate & Environmental Factors

• High Humidity / Road Salt: Moisture and salt spray accelerate corrosion on wiring harness connectors, especially at the throttle body. This leads to intermittent signal loss and high resistance faults.
• Extreme Cold: Moisture inside the throttle body freezes, causing the throttle plate to stick. The PCM commands a movement, sees it doesn't happen, and triggers a shutdown. Old wiring becomes brittle and cracks if disturbed.
• Engine Bay Heat: Wiring and connectors routed too close to hot exhaust components melt or become brittle over time, leading to shorts or open circuits. Plastic gears inside older throttle bodies become brittle and fail.

How to Talk to a Mechanic About This Code

Say this: "I have a P2105 'Forced Engine Shutdown' code and the car is not drivable. Since P2105 is a secondary code, please start by checking for primary codes, analyzing the freeze-frame data, and testing the accelerator pedal sensor, throttle position sensor, and related wiring before recommending a throttle body replacement."

This signals you understand P2105 is a *result* of another failure. It directs the technician to perform a logical diagnosis instead of immediately replacing the most expensive part.

Avoid saying:

• 'My car stalled and the check engine light is on.' (Too vague, invites a wide-ranging diagnostic).
• 'I think I need a new throttle body.' (Leads them to replace it without proper diagnosis).
• 'Just fix it.' (Gives the shop a blank check to replace parts without approval).

Questions to ask before authorizing the repair:

• What was the primary fault code that triggered the P2105?
• Can you show me the live data graphs for the accelerator pedal (APP) and throttle position (TPS) sensors?
• Did you perform a voltage drop test on the throttle body's power and ground wires?
• Is the proposed repair for a failed component, or is it a wiring issue?
• What is the warranty on the parts and labor for this specific repair?

Where to Take It: Dealer vs Independent vs Chain

• Dealer:
  Best for: Vehicles under warranty., Vehicles with known TSBs., Complex diagnostics on luxury European brands.
  Downsides: Highest labor rates., May default to replacing the entire throttle body assembly. (Typical cost: +50% vs. baseline)
• Independent Shop: Best fit for most out-of-warranty vehicles. P2105 is a complex but common code requiring a skilled diagnostician.
  Best for: Out-of-warranty vehicles., Diagnosing common codes on mainstream vehicles., Shops with a strong reputation for electrical diagnostics.
  Downsides: Diagnostic skill varies widely., May lack latest manufacturer-specific software updates. (Typical cost: +0% vs. baseline)
• Chain Shop: AVOID for P2105 diagnosis. The risk of misdiagnosis and unnecessary parts replacement is very high.
  Best for: Simple, routine maintenance.
  Downsides: Technician skill varies dramatically., Lack advanced diagnostic tools., High pressure to upsell parts. (Typical cost: -10% vs. baseline)

When to Walk Away From the Repair

If the total estimated repair cost for the P2105 fault exceeds 40-50% of your car's private-party value, seriously consider selling or trading it in.

• Car worth $3500, fix is $1800: Walk away. The repair cost is over 50% of the car's value. It's not a sound financial decision.
• Car worth $10000, fix is $900: Fix it. The repair cost is less than 10% of the vehicle's value and restores a critical safety function.
• Car worth $5000, fix is $2200: Borderline. The cost is approaching the 50% threshold. Get a second opinion to confirm the diagnosis and cost before proceeding.

What Scan Tool You Need for This Code

Minimum: A scanner that reads and graphs live sensor data for the Accelerator Pedal Position (APP) and Throttle Position (TPS) sensors, and retrieves Freeze Frame data.

A basic $20 code reader only shows 'P2105', which is useless for diagnosis. You need to see the live voltage signals to find the glitch that *caused* the shutdown.

Budget: BlueDriver Pro (~$100) — Connects to your smartphone and provides live data graphing for APP and TPS sensors, reads freeze frame data, and checks for other system codes.

Mid-range: Foxwell NT510 Elite / XTOOL D7 (~$180) — Offers critical bidirectional controls to command the throttle body to open and close. Includes the 'Throttle Relearn' function, mandatory after replacing or cleaning the throttle body.

Professional: Autel MaxiCOM MK808 / MK900 (~$400-600) — Provides full bidirectional control, advanced throttle relearn functions for almost all makes, and graphs multiple data points simultaneously for advanced correlation diagnostics.

Rent vs buy: For a one-time fix, many auto parts stores have a free tool loaner program. If you plan to do your own maintenance regularly, buying a tool like the BlueDriver or Foxwell is a worthwhile investment.

How to Clear the Code After You Fix It

1. Fix the underlying cause (e.g., replace throttle body, repair wiring).
2. Reconnect the battery if it was disconnected.
3. Use an OBD-II scan tool to clear all diagnostic trouble codes.
4. Perform the vehicle-specific throttle body relearn procedure.
5. Complete a full drive cycle to allow readiness monitors to run.

Drive cycle (~20 minutes): Cold start the vehicle and let it idle for 2-3 minutes. Drive in stop-and-go traffic for 5-10 minutes. Drive at a steady speed (around 55 mph) on a highway for 5-10 minutes. Allow the vehicle to cool down completely.

Readiness monitors affected: Comprehensive Component Monitor (CCM), Catalyst (CAT) Monitor, Evaporative (EVAP) System Monitor, Oxygen (O2) Sensor Monitor

Before emissions retest: drive at least 50 miles to fully set monitors.

Watch out for:

• Clearing the code without fixing the root cause results in the code returning immediately.
• Forgetting to perform the mandatory throttle body relearn procedure after replacement or cleaning causes idling and performance issues.
• Not completing a full drive cycle leaves readiness monitors incomplete, causing an automatic emissions test failure.

Will This Fail Emissions / State Inspection?

Yes — this code typically fails an OBD-II emissions inspection.

• California: An active Check Engine Light results in an automatic failure of the smog check. After repairs, a full drive cycle must be completed to set all readiness monitors.
• New York: The NYS DMV vehicle inspection includes an OBD-II scan. An active P2105 code is an automatic failure, and the vehicle cannot be registered until repaired.
• Texas: In counties requiring emissions testing, an illuminated Check Engine Light from a code like P2105 causes the vehicle to fail the inspection.

Most Commonly Affected Vehicles

• Ford Focus, Fusion, Escape, F-150 (2005-2014) — Extremely common due to faulty electronic throttle bodies. Ford issued Customer Satisfaction Program 13N03, extending the warranty to 10 years or 150,000 miles.
• Chevrolet / GMC Silverado, Equinox, Malibu, Sierra (2007-2016) — Caused by 'fretting corrosion' on the throttle body connector pins. The official fix involves applying dielectric grease or replacing the connector pigtail.
• Hyundai / Kia Elantra, Santa Fe, Optima, Sorento (2007-2017) — TSB 21-01-023H-1 regarding a knock sensor software update (Campaign 953) triggers code P1326 and a similar limp mode, often misdiagnosed as a throttle body failure.
• Jeep / Dodge Patriot, Compass, Caliber (2007-2017) — Frequently traced to a failed throttle body assembly. High failure rates make aftermarket options widely available.
• Nissan Altima, Sentra, Rogue (2007-2013) — Linked to a dirty throttle body. Performing the 'Idle Air Volume Relearn' procedure after cleaning is critical; failure to do so mimics a faulty part.
• Subaru Forester, Outback, Impreza (2006-2014) — Caused by electronic throttle body failure or intermittent wiring issues, particularly where the engine harness flexes or passes through the firewall.
• BMW 3-Series (E90), X3, 5-Series (2006-2013) — Points to a failure of the throttle actuator ('Drosselklappe'). Diagnosis is complex due to highly integrated electronics and requires brand-specific diagnostic software.
• Volkswagen/Audi Jetta, Golf, A4 (2010-2016) — Prone to throttle body failures. Aftermarket suppliers offer an 'OE FIX' version with an upgraded non-contact Hall effect sensor designed to be more durable.

Manufacturer-Specific Notes

• Hyundai / Kia: P2105 indicates the engine is in 'Limp-Home mode' because another ETC fault was detected. Separately, Campaign 953 (knock sensor update) triggers a similar 2000 RPM limp mode and code P1326.
• Ford: Internal electronics of the throttle body fail due to contamination on contact-style TPS sensors. Customer Satisfaction Program 13N03 extended the warranty for this part to 10 years/150,000 miles.
• General Motors (Chevy, GMC): The wiring harness connector at the throttle body experiences 'fretting corrosion,' causing an intermittent connection. The fix involves replacing the connector pigtail and applying special terminal grease.
• Volkswagen / Audi: Original throttle bodies are known to fail. Aftermarket solutions use a superior non-contact Hall effect sensor, preventing failures from oil and moisture intrusion.

Real Owner Stories

2012 Ford Escape V6, mileage unknown

Vehicle entered limp mode with wrench light and Check Engine Light. Code P2105 was confirmed by an auto parts store scan.

Outcome: The owner replaced the throttle body at their own expense. The lesson is that even with known issues and warranty extensions, timing is critical.

Lesson: If you own a vehicle known for a specific common failure (like 2009-2013 Fords and throttle bodies), check for warranty extensions or recalls immediately. Don't wait for the failure to occur.

2015 Audi A4, mileage unknown

The car went into limp mode, and a scan revealed code P2105 along with other throttle-related codes.

Outcome: Repairing the wiring and cleaning the throttle body resolved the code without replacing the expensive assembly.

Lesson: Do not automatically replace the throttle body. A thorough inspection of the wiring harness and connectors is a critical first step, as wiring damage produces the exact same symptoms as a failed component.

2010 Chevy Equinox, 25k miles

The owner experienced intermittent reduced power mode, a common symptom preceding a full P2105 shutdown. The throttle body didn't look particularly dirty.

Outcome: This resolved the intermittent reduced power mode, proving that even minor buildup affects sensitive electronic throttle systems.

Lesson: On modern cars, the system is highly sensitive to throttle body cleanliness. A quick cleaning is a low-cost, high-impact diagnostic step to perform before suspecting expensive parts.

How to Prevent This Code From Triggering

• Clean the throttle body. (Every 30,000-50,000 miles.) — Removes carbon and oil deposits that cause the throttle plate to stick, a direct cause of P2105. A clean surface ensures the plate moves freely.
• Apply dielectric grease to the throttle body connector. (Any time the connector is unplugged for service.) — Seals out moisture and prevents fretting corrosion on connector pins, ensuring a stable electrical signal between the PCM and throttle body.
• Perform regular battery and charging system tests. (Annually, especially before winter.) — The electronic throttle system is highly sensitive to voltage. A weak battery provides unstable power, causing communication errors that trigger a false P2105.
• Use high-quality fuel with detergents. (Every fill-up.) — Reduces carbon deposit formation throughout the intake system, lowering the chance of buildup in the throttle body.
• Inspect wiring harnesses for security and condition. (During every oil change.) — Ensures harnesses are not rubbing against hot or sharp engine components, preventing wires from shorting out or breaking.

Frequently Asked Questions

What is the most common misdiagnosis for P2105?

The biggest mistake is immediately replacing the expensive electronic throttle body without comprehensive diagnosis. P2105 is a *reaction* code. A skilled technician first uses Freeze Frame data to identify the primary fault code, then meticulously tests the wiring, grounds, and accelerator pedal sensor before condemning the throttle body.

Can I just clear the P2105 code to get home?

No, clearing the code is unsafe and ineffective. Because P2105 indicates a critical safety fault, the PCM's self-diagnostics run the moment you turn the key. The underlying problem is instantly detected, the code reappears, and the engine is forced back into shutdown mode.

What is the difference between P2104, P2105, and P2106?

They are all fail-safe modes with different levels of severity. P2104 ('Forced Idle') allows the engine to idle only, while P2106 ('Forced Limited Power') allows some reduced power. P2105 ('Forced Engine Shutdown') is the most severe, where the PCM completely kills the engine for safety.

I was quoted $1,200 for a throttle body replacement. Is this a scam?

It depends on the vehicle. On a common domestic car, an aftermarket part is under $150, making a DIY repair possible for under $200. On a luxury European brand or turbocharged engine, the OEM part alone easily exceeds $700, making a $1,200 bill with diagnostics and labor entirely plausible.

Why did my car shut down in the middle of the highway?

The car's computer detected a problem where it could no longer reliably control the engine's speed. To prevent the car from accelerating unexpectedly or becoming uncontrollable, it executed its safest protocol. It shut down the engine by completely closing the throttle plate.

Can a low battery cause a P2105 code?

Yes, absolutely. The entire electronic throttle control system relies on stable voltage. A weak battery or failing alternator causes erratic signals and communication dropouts, which the PCM misinterprets as a critical system failure and triggers a shutdown.

The mechanic wants to replace the PCM. Is that necessary?

It is extremely rare for the PCM to be the cause of a P2105 code. PCM replacement is the absolute last resort. It should only be considered after the throttle body, all related sensors, and all associated wiring are professionally tested and confirmed to be in perfect working order.

Key Takeaways

• Code P2105 is a safety override, not a component failure, meaning the PCM forced a 0 RPM engine shutdown because it detected a critical throttle system fault.
• Driving with an active P2105 code is impossible; the vehicle will stall or refuse to start, requiring an immediate tow to a safe location.
• Diagnosis must start by reading the freeze frame data to find the primary trigger code (like P2135 or P0121), as P2105 is only the symptom.
• Before spending $400+ on a new throttle body, perform a 100mV voltage drop test on the ground circuit to rule out a cheap wiring failure.