P0105: Manifold Absolute Pressure / Barometric Pressure Circuit Malfunction

What it means

The ECU detects a general electrical malfunction in the manifold absolute pressure (MAP) or barometric pressure sensor circuit. Signal missing, implausible, or wiring broken. Generic fault when no more specific MAP code applies.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The manifold absolute pressure (MAP) sensor measures pressure in the intake manifold, and the ECM uses it to estimate engine load; some systems also monitor a barometric pressure signal. P0105 sets when the relevant pressure-sensor circuit has a general electrical or signal fault that does not fit a more specific low or high condition.

Common causes

Most likely first.

1. MAP sensor failed
2. Vacuum hose to MAP sensor cracked or disconnected
3. MAP wiring or connector fault

Symptoms

• Check engine light on

How to diagnose it

1. Read stored and pending codes and freeze-frame data, then compare live MAP and barometric readings, if available, with key-on engine-off and idling conditions.
2. Inspect the MAP sensor connector and harness for loose pins, corrosion, damaged insulation, or an unplugged connection.
3. If the sensor uses a vacuum hose, check that the hose is connected, unobstructed, and free of cracks.
4. Test circuit power, ground, signal continuity, and shorts using the wiring diagram and manufacturer's specification.
5. Check the sensor port and intake manifold area for blockage or leaks that could distort the pressure reading.
6. If the circuit and hose are sound but the pressure signal remains implausible, test or replace the MAP sensor as indicated by the manufacturer's procedure.

Common fixes

• Reconnect a loose MAP connector or repair damaged terminals and wiring.
• Reconnect or replace a cracked or disconnected MAP vacuum hose, where fitted.
• Clear debris from a blocked sensor port using an appropriate method.
• Repair a leaking intake manifold gasket if testing confirms a leak.
• Replace a MAP sensor that fails signal checks after its wiring and pressure path are verified.

Can I keep driving?

A short, gentle drive may be possible if the engine runs normally, but inaccurate pressure data can affect fueling and cause hesitation or stalling. Avoid hard acceleration and stop if the engine becomes unstable.