Fuel and air

P0105 — Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Fault

Severity: medium Drive with care, to a shop

What P0105 means

The engine control unit constantly monitors the manifold absolute pressure (MAP) sensor, and on some vehicles a barometric pressure signal as well. It uses this to estimate engine load and calculate fuel delivery and ignition timing. P0105 is set when the signal is out of range or does not agree with other data such as throttle position and engine speed.

Symptoms

  • Check Engine light on
  • Rough or unstable idle
  • Weak acceleration and loss of power
  • Poor fuel economy
  • Hesitation or stumbling when you press the gas
  • Stalling at idle or when lifting off the throttle
  • Possible misfires

Possible causes

  1. Failed MAP sensor
  2. Damaged wiring or corroded, loose connector pins at the sensor
  3. Open or shorted signal, 5 V reference or ground wire
  4. Intake vacuum leak or cracked MAP sensor vacuum hose
  5. Clogged or dirty pressure port to the sensor
  6. Faulty BARO sensor (if separate)
  7. Failed PCM/ECM (rare)

How to diagnose

  1. Read all codes and freeze-frame data and look for other air or fuel codes
  2. Inspect the MAP sensor, connector and harness for corrosion, cracks, chafing or oil in the plug
  3. Check the sensor's vacuum hose and the intake tract for leaks
  4. With key on, engine off, compare the MAP reading to ambient barometric pressure; they should be close
  5. At idle, confirm the reading drops well below atmospheric and changes smoothly as the throttle opens
  6. Use a multimeter to check 5 V reference, ground and signal voltage at the sensor connector
  7. Test the wires back to the PCM for opens and shorts
  8. If wiring is good, swap in a known-good sensor and recheck

Common fixes

  • Replace the MAP sensor
  • Repair the wiring or replace a damaged connector
  • Replace vacuum hoses and fix intake leaks
  • Clean the terminals and the sensor pressure port
  • Reflash or replace the PCM (very rare, only after everything else is ruled out)

P0105 on different brands

Ford · manuals
Ford uses an extended P0105:16 format on 2024–2025 gasoline engines, meaning MAP/BARO sensor circuit voltage is below the threshold. It describes the condition the monitor detected, not proof that the sensor itself has failed.

Questions and answers

What does code P0105 mean?

It means a fault in the manifold absolute pressure or barometric pressure sensor circuit. The PCM gets a bad signal and cannot calculate the air-fuel mixture and timing accurately.

Can I drive with a P0105 code?

Briefly and carefully, such as to a shop. The engine may misfire, lose power or stall, and fuel use will go up. Don't put off the repair.

Do I always need to replace the MAP sensor?

No. The problem is often a connector, wiring or a vacuum leak. Check power, ground, signal and hoses first, and replace the sensor only if the rest is fine.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.