P0105: Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction
The P0105 code indicates a malfunction in the Manifold Absolute Pressure (MAP) or Barometric Pressure (BARO) sensor circuit. The Engine Control Module (ECM) detects an electrical issue such as an open circuit, short circuit, or out-of-range signal from the sensor. This sensor measures intake manifold pressure to calculate air density and fuel delivery. A fault can cause incorrect air-fuel mixture, leading to performance issues.
1. Most Common Causes
- Faulty MAP/BARO sensor
- Open or shorted wiring in sensor circuit
- Poor electrical connection at sensor connector
- Vacuum leak in intake manifold
- Faulty ECM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine hesitation or stalling
- Poor acceleration or rough idle
- Decreased fuel economy
- Black smoke from exhaust (rich mixture)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect MAP sensor connector and wiring for damage or corrosion.
Step 3: Check for vacuum leaks using a smoke machine or propane enrichment.
Step 4: Test MAP sensor signal voltage with a multimeter (typically 0.5-4.5V at key on, varies with vacuum).
Step 5: Compare sensor reading to a known good sensor or use a scan tool to monitor pressure.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the engine may run poorly, stall, or cause further damage. Short trips to a repair shop are acceptable if the vehicle is drivable.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a new MAP sensor plus labor. Diagnostic fees may apply if you take it to a shop.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.