P0106 OBD2 Code Guide
P0106 is a sensors diagnostic trouble code. Use this hub to understand the plain meaning, the first checks to run, and which vehicle-specific guides may be more useful before replacing parts.
MAP/Barometric Pressure Circuit Range/Performance
Code P0106 indicates that the Powertrain Control Module (PCM) has detected an output voltage from the Manifold Absolute Pressure (MAP) sensor that is inconsistent with the expected range for the current engine operating conditions, such as engine RPM, throttle position, and barometric pressure. This discrepancy suggests a potential issue with the MAP sensor itself, its electrical circuit, or the engine's vacuum system, leading to inaccurate fuel delivery and ignition timing.
Code verification standard
P0106 is published with SAE J2012 / ISO 15031-6 code structure plus OBD2 P0106 diagnostic context.
First checks
- - Read all stored and pending codes before clearing anything.
- - Save freeze-frame data so you know speed, load and temperature when the code set.
- - Inspect wiring, connectors, fuses, hoses and obvious leaks tied to the named system.
- - Compare live data against realistic values before buying sensors or modules.
- - Clear the code only after repair and complete a drive cycle to confirm it does not return.
P0106 diagnostic path
- 1Visual Inspection & Vacuum Check: Begin by visually inspecting the MAP sensor and its electrical connector for any signs of damage, corrosion, or loose connections. Crucially, check all vacuum lines connected to the MAP sensor and the intake manifold for cracks, disconnections, or leaks. A common cause for P0106 is a vacuum leak affecting the MAP sensor's reading.
- 2MAP Sensor Voltage & Signal Test: With a scan tool, monitor the MAP sensor's live data. Compare the sensor's voltage reading at key-on-engine-off (KOEO) to the barometric pressure (BARO) sensor reading (if available) – they should be very close. Then, start the engine and observe the MAP voltage at idle; it should drop significantly and remain steady. Perform a vacuum test directly on the MAP sensor port using a hand-held vacuum pump to verify if the sensor's voltage output changes smoothly and proportionally with varying vacuum levels.
- 3Circuit Integrity Test: Disconnect the MAP sensor and perform voltage and ground checks at the sensor's electrical connector using a multimeter. Verify the 5V reference voltage and a good ground. Then, check the signal wire for continuity back to the PCM and for any shorts to voltage or ground. Wiggle-test the harness while monitoring live data to detect intermittent connection issues.
- 4PCM Software/Hardware Check: If the sensor, wiring, and vacuum system all test good, consider checking for any available PCM software updates, as sometimes calibration issues can trigger this code. In rare cases, an internal PCM fault could be the cause, but this should only be considered after thoroughly ruling out all other possibilities.
Verify before repair
- - Replace the faulty Manifold Absolute Pressure (MAP) sensor.
- - Repair or replace damaged, cracked, or disconnected vacuum lines leading to the MAP sensor or intake manifold.
- - Repair corroded, loose, or damaged wiring and connectors in the MAP sensor circuit.
- - Address significant intake manifold vacuum leaks (e.g., faulty gaskets, PCV system issues) that are affecting the MAP sensor's ability to read manifold pressure accurately.
Vehicle-specific pages to check next
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