P0105 Code: Manifold Absolute Pressure (MAP) / Barometric Pressure Circuit Malfunction
Note: We do not currently have verified model-specific diagnostic data for the Bmw M3. The symptoms and fixes listed below are the standard generic OBD2 guidelines for the P0105 code. Always consult a factory service manual before replacing parts.
What does this mean?
The P0105 code indicates that the Powertrain Control Module (PCM) has detected an electrical malfunction within the Manifold Absolute Pressure (MAP) sensor circuit or the Barometric Pressure (BARO) sensor circuit. The MAP sensor measures the absolute pressure within the intake manifold, providing crucial data to the PCM for calculating engine load, fuel delivery, and ignition timing. A BARO sensor, often integrated into the MAP sensor or PCM, measures atmospheric pressure. A "circuit malfunction" means the PCM is receiving an implausible signal, no signal, or a signal outside its expected operating range, which can severely impact engine performance, fuel economy, and emissions.
How serious is this code?
Driving with a P0105 code can lead to significant drivability issues, including rough idle, stalling, poor acceleration, reduced fuel economy, and increased emissions. The PCM may enter a "limp home" mode, using default values, which can cause unpredictable engine behavior. While it might not immediately cause a breakdown, prolonged driving can lead to further engine damage due to incorrect fuel mixture and timing. It is advisable to diagnose and repair this issue promptly.
Diagnostic system: Sensor circuit and live data
On a Bmw M3, the P0105 code should be diagnosed as part of the sensor circuit and live data group. Related codes and live data from this same system can change the repair priority, so avoid replacing parts from the code name alone.
Most Common Causes for Bmw M3
- Faulty MAP (Manifold Absolute Pressure) sensor
- Damaged, chafed, or broken wiring harness
- Corroded or loose electrical connector
- Vacuum leak in intake system
Symptoms to Watch For
- Check Engine Light is illuminated
- Rough or unstable idle
- Engine stalling or dying unexpectedly
- Poor acceleration or sluggish response
- Decreased fuel economy
- Difficulty starting the engine
Before replacing parts, check these first
- Inspect the connector for corrosion, broken locks, oil intrusion, or heat damage.
- Verify 5V reference, ground, and signal with a multimeter where applicable.
- Compare live sensor data to realistic engine temperature, pressure, airflow, or throttle values.
- Check for blown fuses, weak battery voltage, and damaged connectors before buying major parts.
Live data to compare
- 5V reference, ground, and signal voltage
- Sensor value compared with realistic engine conditions
- Connector wiggle-test result
How to Diagnose
Common Mistakes
Replacing the named sensor without testing power, ground, signal, and wiring continuity first. Always confirm the fault with freeze-frame data, live data, visual inspection, and circuit checks before spending money on parts.
Repair verification
After the repair, clear P0105, complete a drive cycle, and confirm the monitor runs without the code returning. Save the before/after scan report if the vehicle needs emissions inspection.
Frequently Asked Questions
Can I drive with the P0105 code?
If the check engine light is solid, you can usually drive to a safe location or mechanic. If the light is flashing, pull over immediately to prevent catastrophic engine or catalytic converter damage.
Will the P0105 code clear itself?
Once the underlying problem is fixed, the engine computer will run its self-checks. If it passes over several drive cycles, the light will turn off automatically. You can also clear it immediately using an OBD2 scanner.
Will this code fail an emissions test?
Yes. If the Check Engine Light is on due to the P0105 code, your Bmw will automatically fail an OBD2 plug-in emissions or smog test.
What should I check first for P0105?
Inspect the connector for corrosion, broken locks, oil intrusion, or heat damage. Verify 5V reference, ground, and signal with a multimeter where applicable. Compare live sensor data to realistic engine temperature, pressure, airflow, or throttle values.
Join the Discussion
Repair Estimate
Fuse, connector, wiring, cleaning, or basic inspection
Major component replacement after live data and circuit tests confirm failure
Sensor replacement can be moderate cost, but wiring and connector repairs are common and cheaper.
DIY Difficulty
Can usually be performed at home with basic hand tools.