P0105🔧 Air intake / manifold absolute pressure (MAP) sensorDrive with caution, fix soon

P0105: MAP/Barometric Pressure Circuit Malfunction (Meaning, Causes, Fixes)

Reviewed 2026-10-25 · Based on 2 cited source(s)

What P0105 means

The MAP sensor measures the rise and fall of air pressure inside the intake manifold and turns it into a voltage: high when manifold pressure is high (engine under load) and low when the manifold is under vacuum (idling or coasting). The PCM uses it to set the air-fuel ratio, ignition timing and several emissions systems. It is a generic code for OBD-II vehicles, and the repair steps vary by make and model. The two sources describe how it sets a little differently. RepairPal says P0105 sets when the sensor's output stays below 0.5 volts or above 4.5 volts for several seconds while RPM and throttle position are changing. OBD-Codes.com says the PCM cross-checks the MAP signal against the throttle position sensor (TPS): if the MAP reading doesn't change right after the throttle moves, or the TPS shows the engine under load while the MAP shows it coasting, the code sets. Because of that, OBD-Codes.com lists a bad TPS or TPS connector among the causes, which RepairPal does not. OBD-Codes.com also notes the code shouldn't normally set with the MAP stuck at a very low voltage, but includes that case because it can't rule it out for every vehicle. Related MAP sensor codes are P0106 (range/performance), P0107 (low), P0108 (high) and P0109 (intermittent).

Severity: can I keep driving?

Drive with caution, fix soon

Get it checked soon. RepairPal rates P0105 Urgent and notes it can cause hard starting, poor fuel economy and poor engine performance. OBD-Codes.com gives no rating but lists a rough-running or rich-running engine, no idle, backfiring and misfires, while saying that in some cases the check engine light is the only sign. If the engine won't idle, misfires or backfires, avoid driving it (especially in traffic) until it's fixed, and don't ignore a flashing check engine light.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. MAP sensor vacuum hose disconnected or plugged (OBD-Codes.com), or a split seal where the sensor plugs into the manifold (RepairPal)
  2. Bad MAP sensor (OBD-Codes.com, RepairPal)
  3. Intake manifold vacuum leaks (RepairPal)
  4. Damaged, faulty or corroded MAP sensor wiring or connector (OBD-Codes.com, RepairPal)
  5. Signal circuit shorted to the 5-volt reference, open signal circuit, or lost ground to the MAP sensor or TPS (OBD-Codes.com)
  6. Bad throttle position sensor or TPS connector (OBD-Codes.com)
  7. Bad PCM (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Read all stored codes and save the freeze frame data. Check the MAP vacuum hose for being loose, cracked or plugged, and the sensor seal if it plugs straight into the manifold.
  2. With the key on and engine off, read the MAP sensor value on a scan tool. OBD-Codes.com says it should be about 4 volts at sea level, dropping roughly half a volt per 1,000 feet of altitude (varies by model), and should roughly match the barometric reading if the car also has a MAF sensor.
  3. Watch the MAP reading on a test drive. RepairPal says it should rise and fall with engine speed and load, typically 4 volts or more when accelerating and 1 volt or less when decelerating. OBD-Codes.com says about 1 volt at idle and approaching 4.5 to 5 volts at wide open throttle, and that comparing MAP to TPS in freeze frame data shows whether the readings make sense together.
  4. Do a vacuum pump test on the sensor while watching the scan tool and wiggling the harness. RepairPal says the voltage should drop steadily from about 5 volts to under 0.5 volts as you apply 18 to 20 inches of vacuum. OBD-Codes.com words this as the reading changing as vacuum is applied, and says if it doesn't change and the hose is clear, the sensor is usually bad.
  5. Check the sensor connector with the key on and engine off for a steady 5-volt reference and a good ground, and check the signal wire for continuity to the PCM. Use a wiring diagram for your vehicle to identify the wires.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The engine won't idle, misfires or backfires
  • The check engine light is flashing
  • The MAP sensor reads normally on the vacuum test but the code keeps coming back
  • You suspect a stuck-open EGR valve or idle air control problem, which RepairPal lists as common misdiagnoses
  • Wiring checks need a diagram or PCM connector access you don't have

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0105?

It's best not to put it off. RepairPal rates it Urgent, and OBD-Codes.com lists symptoms like no idle, misfires and backfiring. If the car runs normally, drive gently and get it checked soon; if it won't idle, misfires or the check engine light flashes, avoid driving it.

Should I just replace the MAP sensor?

Not before checking. RepairPal lists replacing the MAP sensor as a common misdiagnosis when the real cause is an intake vacuum leak, a stuck-open EGR valve or a bad idle air control motor. Check the vacuum hose, wiring and a vacuum pump test first.

What's the difference between P0105 and P0106?

P0105 is the general MAP/barometric pressure circuit code. P0106 is the range/performance code, meaning the sensor reports a value that doesn't make sense for the engine's operating conditions. P0107 and P0108 are the specific low and high voltage codes.

How much does it cost to fix P0105?

Neither source gives a repair cost for P0105. A loose or cracked vacuum hose is a much smaller fix than a sensor or PCM, so find the cause before buying parts.

Sources

  1. OBD-Codes.com: P0105 MAP Circuit Malfunction
  2. RepairPal: P0105 Manifold Absolute Pressure/Barometric Pressure Circuit (rated Urgent)

Last reviewed 2026-10-25. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.