What P0106 Means
P0106 means the manifold absolute pressure (MAP) or barometric pressure sensor signal is outside the range the PCM considers plausible, given other engine data like throttle position and engine speed. The MAP sensor measures vacuum or pressure inside the intake manifold, which the PCM uses — either as the primary load input on speed-density fuel systems, or as a cross-check alongside the MAF sensor on combined systems — to calculate engine load and fine-tune fuel and ignition timing accordingly. A range/performance fault specifically means the signal isn't outright dead, but it also isn't tracking correctly with what the engine is actually doing. This distinguishes P0106 from a simple high or low voltage code: the sensor is producing a signal, but that signal doesn't correlate properly with throttle position or RPM changes, which usually points to a vacuum leak, a partially clogged sensor port, or a sensor that's drifted out of calibration rather than a completely dead component.
Common Causes
- Vacuum leak in the intake manifold or connected hoses, altering the pressure the sensor actually reads
- MAP sensor vacuum port or hose clogged with carbon or debris, dampening its response
- Faulty or drifting MAP sensor no longer reading accurately across its full range
- Damaged, corroded, or loose MAP sensor wiring and connector
- Throttle body or intake gasket leak allowing unmetered air into the manifold
- Carbon buildup inside the intake manifold restricting normal airflow patterns
Symptoms You Might Notice
- Check Engine Light on, sometimes with a rough or fluctuating idle
- Hesitation or poor throttle response during acceleration
- Noticeably reduced fuel economy
- Engine may run rich or lean intermittently depending on how the bad signal skews the PCM's fuel calculation
- Occasional stalling at idle if the reading is bad enough to badly skew fuel delivery
What to Check First
- 1
Inspect all vacuum hoses connected to the intake manifold and MAP sensor for cracks, splits, or loose connections
- 2
Check the MAP sensor's vacuum port and hose for carbon buildup or blockage that could be damping its response
- 3
Use a scan tool to watch live MAP sensor data while snapping the throttle, confirming the reading rises and falls smoothly and promptly with throttle input
- 4
Inspect the sensor wiring harness and connector for corrosion or a poor connection
- 5
If the sensor and wiring check out, test for intake or throttle body vacuum leaks using a smoke test or carb cleaner spray method around gasket surfaces while the engine idles
Frequently Asked Questions
How is P0106 different from a MAP sensor voltage code like P0107 or P0108?
P0107 and P0108 mean the signal is stuck at an implausibly low or high fixed value. P0106 means the signal is moving and changing, but not correlating properly with what the engine's actually doing — which usually points more toward a vacuum leak or a drifting sensor than an outright dead one.
Can a vacuum leak really cause this code?
Yes, and it's one of the most common causes. A vacuum leak changes actual manifold pressure independently of what the MAP sensor 'expects' based on throttle position, so the PCM sees pressure readings that don't line up with the rest of its data.
Will P0106 hurt my engine if I keep driving?
It's unlikely to cause immediate damage, but a persistently inaccurate MAP reading means your fuel and timing calculations are off, which can hurt fuel economy and drivability, and in a sustained rich or lean condition, contribute to spark plug fouling or catalytic converter stress over time.
Reviewed by Emmanuel Erere, Auto Mechanic. Causes and diagnostic steps checked for workshop accuracy.