P0105 — Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction

powertrain (engine/transmission)

Is it safe to drive?

Limited operation recommended P0105 can cause unstable idle, hesitation, or stalling because the controller may be calculating fuel delivery from an invalid pressure signal. Short trips may be possible if the engine runs smoothly, but diagnosis is prompt; stop driving if the engine stalls or enters reduced-power mode.

Typical symptoms

The check-engine light illuminates and P0105 is stored in the powertrain controller
Engine idle speed is rough, unstable, or unusually high
The engine hesitates or briefly stalls while accelerating
Fuel consumption increases while engine output feels reduced
The vehicle may enter a reduced-power or default operating mode

Common causes

A faulty MAP/barometric pressure sensor producing an abnormal reference, ground, or signal voltage
An open circuit, short circuit, or poor ground in the MAP sensor wiring harness
Corrosion, damaged terminals, or a loose connector at the MAP sensor or powertrain control module
A restricted, cracked, or disconnected vacuum hose or manifold pressure port on a hose-referenced MAP sensor
Oil or contamination inside the MAP sensor that causes an erratic pressure reading
A powertrain control module reference or input failure, although this is less common

How to diagnose with an OBD scanner

Inspect the MAP sensor circuit Locate the MAP/barometric pressure sensor and examine its connector, wiring, and mounting area. Look for corroded pins, stretched terminals, damaged insulation, pinched wires, or a connector that does not fully latch.
Read live pressure data with a scanner Connect an ELM327 adapter with a suitable diagnostic app or use AIScanAuto to read stored codes and live MAP or absolute-pressure data. Confirm that P0105 is present and compare the displayed value at key-on and during idle with the service specification for that vehicle.
Test reference, ground, and signal voltage With the ignition commanded on, back-probe the MAP sensor terminals and verify its reference voltage, ground voltage, and signal voltage against the service manual. The signal should change smoothly as manifold vacuum changes; an abrupt fixed value, zero volts, or a short to power points to a circuit or sensor fault.
Perform a wiggle and vacuum check While monitoring the live MAP data, lightly move the sensor connector and harness to expose an intermittent connection. If the sensor uses a vacuum hose, inspect the hose, manifold port, and diaphragm for restriction, leakage, cracks, or oil contamination.
Repair and verify P0105 Repair damaged wiring or terminals, restore a proper ground and reference, replace the defective MAP sensor, or correct the vacuum leak. Clear the code, confirm the live pressure reading is plausible, and road-test the vehicle to verify that P0105 does not return.

Approximate repair cost

A typical independent-shop cost is $150 USD to $600 USD for diagnosis, MAP sensor replacement, connector or wiring repair, or correction of a vacuum leak. More extensive control-module work may cost more. Figures are estimates and vary by region.

Common questions

What does P0105 mean on this vehicle?

P0105 means the controller detected a malfunction in the MAP/barometric pressure circuit, such as an invalid sensor signal, wiring problem, poor ground, or defective sensor.

Can I continue driving with P0105 stored?

You can cautiously drive if the engine idles smoothly without stalling, but P0105 can affect fuel calculation and cause hesitation or loss of power. Repair it promptly.

Does P0105 always require a MAP sensor replacement?

No. The sensor is a common cause, but P0105 can also result from damaged wiring, a bad connector, an incorrect ground, or a vacuum leak on a hose-referenced design.

Why might P0105 return after the MAP sensor is replaced?

P0105 can return if the replacement sensor is faulty, its connector pins remain corroded, a reference or ground circuit is open, or a vacuum hose continues to leak. Scan live data and test the circuit before replacing another component.

When your scan tool pulls code P0105, the engine control unit is telling you it cannot trust the signal from the sensor that measures pressure in the intake manifold. The full description reads "Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction," and it falls under the powertrain category since it affects how the engine manages air and fuel. This is not a simple electrical open or short — the module ran a self-test on the sensor and its surrounding circuitry, and something came back out of spec.

The manifold absolute pressure sensor (MAP) works alongside the mass airflow sensor (MAF) and throttle position sensor to give the ECU a complete picture of how much air is entering the engine. On many platforms the barometric pressure reading shares a circuit with the MAP or uses a separate reference sensor. The ECU compares these pressure readings against expected values based on rpm, throttle angle, and other inputs. When the live data does not match the model the engineers programmed, P0105 gets set — typically after the fault persists across multiple drive cycles. The stored freeze frame data records engine speed, load, coolant temperature, and vehicle speed at the exact moment the problem appeared, which is useful for recreating the failure condition.

The nature of a "circuit malfunction" code means the problem could live in the wiring, the connector, the sensor itself, or even the control module driver that processes the signal. This is why a systematic approach matters — swapping parts blindly wastes money when the real culprit might be a corroded pin or a software bug.

Symptoms of P0105

The engine idles roughly, bouncing between higher and lower rpm than normal
The vehicle enters limp-home mode with noticeably reduced power output
The engine stalls when decelerating or coming to a stop
The Check Engine light stays illuminated on the dashboard
Throttle response feels sluggish or delayed when pressing the accelerator pedal

Common Causes of P0105

The manifold absolute pressure or barometric pressure sensor has failed internally
Wiring or connectors related to the throttle and intake air metering circuits are damaged, corroded, or loose
The electronic throttle motor or throttle plate mechanism is sticking or failed
The mass airflow sensor or MAP sensor is contaminated with dirt or oil or has stopped working
The throttle body is dirty with carbon buildup, preventing the plate from moving freely
The throttle position sensor or accelerator pedal position sensor is faulty
Intake air leaks exist downstream of the MAF sensor, throwing off the pressure readings
The engine control module itself has a software or hardware fault affecting the throttle driver

How to Diagnose P0105

Plug in an OBD2 scanner, verify that P0105 is stored in permanent memory, and record the freeze frame data right away. This snapshot tells you what the engine was doing when the failure occurred and guides your next steps.
Scan for any other diagnostic trouble codes. Related codes often point to the actual root cause — for example, a throttle position sensor fault may explain why the MAP/MAF circuit test failed. Check for any applicable technical service bulletins from the manufacturer; some P0xxx codes have known fixes or calibration updates.
Perform a visual inspection of the wiring harness and connectors feeding the throttle body, MAP sensor, and MAF sensor. Look for frayed wires, broken insulation, moisture intrusion, bent pins, or loose connections.
If your diagnostic scanner supports actuator tests, command the manifold absolute pressure sensor to respond directly. A component that ignores the command or returns no movement is confirmed as defective.
Observe the live data stream for throttle position, MAF grams per second, and MAP voltage while gently pressing and releasing the accelerator pedal. Values should change smoothly and proportionally; spikes, drops, or frozen readings indicate a problem.
Remove and inspect the throttle body for carbon buildup. Clean it with appropriate solvent, verify the plate swings freely with no binding, and reinstall. Clear P0105 from memory, then drive the vehicle through a complete drive cycle that reproduces the freeze frame conditions. Recheck whether the code returns.

Repair Options for P0105

Depending on what your diagnosis uncovers, the following repairs apply:

Throttle body replacement: $250–$700 (parts and labor). This is the full assembly including the throttle plate motor and position sensors built in.
MAF or MAP sensor replacement: $150–$400 (parts and labor). Individual sensors vary by application, but this covers most common setups.
Throttle body cleaning: $80–$200 (labor at independent shops). This is the least expensive option when carbon buildup is the sole issue.

Total Cost to Fix P0105

The total invoice depends entirely on which part is actually at fault. A cleaning might resolve the issue for under $200, while a full throttle body replacement can run $700 or more depending on your vehicle and local labor rates. Independent shop pricing typically falls in the ranges above. Spending $50–$100 on a thorough diagnosis before purchasing any parts is the smartest first move — the most expensive component is rarely the one that needs replacing.

Can You Drive with P0105?

Proceed with caution. Many throttle-related faults trigger limp-home mode, cutting engine power significantly. You can typically reach a repair facility at low speed, but highway driving is not advisable. If the engine stalls completely or the accelerator pedal loses response, stop driving immediately and have the vehicle towed. The Check Engine light will remain on until the underlying fault is resolved.