OBD-II trouble code
P0105: Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction
The engine computer sees an electrical fault in the MAP (manifold absolute pressure) sensor circuit — the signal is missing, stuck, or not changing the way it should.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air Metering
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $350
- DIY difficulty
- Intermediate DIY
What does P0105 mean?
The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold, which the engine computer uses — sometimes together with or instead of a mass airflow sensor — to calculate engine load and how much fuel to inject. Many vehicles also use it to read barometric pressure at key-on for altitude compensation. P0105 is the broad "circuit malfunction" code for this sensor: the computer sees a signal that is missing, fixed, or electrically implausible.
Where P0107 and P0108 flag the signal specifically stuck low or high, P0105 sets when the circuit itself misbehaves — an open or intermittent wire, a bad connector, a 5-volt reference or ground problem, or a sensor whose output never changes with engine load. Because fueling leans heavily on this input, the computer often substitutes a fallback value, so the engine may run — just poorly.
Diagnosis is usually simple: verify the sensor gets its 5-volt reference and ground, confirm the signal changes smoothly between key-on (high, near barometric) and idle (low vacuum), and inspect the vacuum hose or port for cracks or clogging on remote-mounted sensors.
Common causes
- Failed MAP sensor
- Open, shorted, or chafed wiring in the MAP circuit
- Corroded or loose sensor connector
- Missing 5-volt reference or bad sensor ground
- Cracked, blocked, or disconnected vacuum hose to the sensor
- Contamination (oil/carbon) on the sensor element
Symptoms
- Check engine light on
- Rough or surging idle
- Hesitation or stumble under acceleration
- Poor fuel economy, rich or lean running
- Hard starting in some cases
- Black smoke from a rich fallback strategy
Diagnostic steps
- 1.Scan and note freeze-frame data; check for companion codes (P0106-P0108, lean/rich codes).
- 2.Inspect the MAP sensor connector and wiring for corrosion, chafing, or a loose fit.
- 3.Key on, engine off: confirm the MAP reading roughly matches barometric pressure; at idle it should drop to a steady vacuum reading.
- 4.Verify 5-volt reference and ground at the connector with a meter.
- 5.Check the vacuum hose or manifold port for cracks, oil, or blockage.
- 6.Replace the sensor only after wiring and vacuum supply check out; clear codes and road-test.
Repair cost
$100 – $350
MAP sensors are inexpensive ($30-$120) and usually accessible, so most repairs are on the low end. Wiring repairs vary. The sensor is often blamed when the real fault is a connector or vacuum hose — verify before replacing.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with map sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.