P0106 Code: MAP/Barometric Pressure Sensor Range/Performance
The MAP sensor works electrically, but its pressure reading doesn't fit what the engine is actually doing.
At a glance
Severity: Low
- Meaning
- MAP/Barometric Pressure Sensor Range/Performance
- System
- Fuel & Air Metering · Powertrain
- Safe to drive?
- Yes, short term
- Typical repair cost
- $0–$700
- DIY difficulty
- Moderate
P0106 means the MAP signal stays inside its electrical limits but makes no sense next to other data. The PCM runs several plausibility checks: at key-on the reading must match barometric pressure, at idle it must show strong vacuum, and as the throttle opens it has to rise in step with throttle angle, MAF airflow and rpm. When the sensor lags, sticks or disagrees with that model, the code sets. Quite often the sensor is faithfully reporting a real problem, because a vacuum leak, an EGR valve stuck open, a restricted exhaust or late valve timing all change the actual pressure in the manifold. The remaining cases are a plugged sensor port or hose, or a replacement sensor with the wrong pressure range.
Can I keep driving? Generally fine to drive. Since the root cause may be a vacuum leak or a mechanical problem, keep an eye on idle quality and power; if misfires or a real loss of power show up, get it checked before driving further.
How to read P0106
- P Powertrain
- 0 Generic (SAE)
- 1 Fuel & air metering
- 06 Specific fault
Symptoms
- Check engine light on, often without any other complaint
- High or hunting idle when a vacuum leak is behind it
- Hesitation or weak pull under load
- Rough idle and stalling when an EGR valve sticks open
- Hissing or whistling from the engine bay
- Worse gas mileage
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Vacuum leak: cracked hose, leaking intake gasket, PCV line or brake booster hose
- Sensor port or connecting hose plugged with oil or carbon, or hose kinked or split
- EGR valve stuck open, raising manifold pressure at idle
- Weak engine vacuum from late valve timing, low compression or a restricted exhaust
- MAP sensor slow to respond or drifting
- Wrong pressure-range sensor installed, or barometric reading error
Diagnosis step by step
Compare MAP with barometric pressure before start
After the engine has been off a few minutes, compare MAP with the scanner's BARO value or the station pressure for your area. They should agree within about 3 kPa (roughly 1 inHg). A sensor that shows 90 kPa near sea level before the engine is even running has drifted.
Tools: OBD-II scanner
Watch idle vacuum and a throttle snap
A healthy non-turbo gas engine idles at about 25 to 35 kPa. Snap the throttle: MAP should jump almost to barometric pressure immediately, then dip below the idle value, around 15 to 20 kPa, as the throttle snaps shut, before settling. A slow, flattened response points at the sensor or a clogged port.
Tools: OBD-II scanner
Cross-check with a mechanical vacuum gauge
Tee a vacuum gauge into a manifold port. A steady 18 to 21 inHg at idle equals roughly 30 to 40 kPa MAP at sea level. If gauge and scanner agree, the sensor is honest and the engine has a real vacuum problem; if they disagree, suspect the sensor or its hose.
Tools: Vacuum gauge, OBD-II scanner
Smoke-test the intake
With the engine off, feed smoke into the intake after the throttle and look for wisps at vacuum hoses, the PCV valve, the intake gasket, the brake booster line and the throttle body gasket. Small leaks that barely hiss at idle show up clearly this way.
Tools: Smoke machine
Rule out EGR and exhaust restriction
If idle vacuum is low but steady, check whether the EGR valve is closed; on electronic valves, command it shut with the scan tool and watch MAP drop. A vacuum reading that slowly sinks while you hold 2,500 rpm points at a clogged catalytic converter or muffler.
Tools: Vacuum gauge, OBD-II scanner
Bench-test the sensor with a hand vacuum pump
With the sensor connected and back-probed, apply vacuum in steps of about 5 inHg. The signal should drop smoothly and hold steady at each step, reaching roughly 1.2 V at 20 inHg on a typical non-turbo sensor; a reading that creeps or lags is a worn sensor.
Tools: Vacuum gauge, Multimeter
Where the parts are
- 1MAF sensor
- 2Turbocharger
- 3Throttle body
- 4Intake manifold
- 5Fuel injector
- 6EGR valve
- 7Fuel pump
- 8Thermostat
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Replace cracked vacuum or PCV hose | Yes | $10–$120 |
| Clean sensor port or replace sensor hose | Yes | $0–$60 |
| Replace MAP sensor | Yes | $60–$250 |
| Replace intake manifold gasket | No | $250–$700 |
| Clean or replace EGR valve | No | $150–$600 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Field data
| Ford | 11 | Escape, Explorer, Focus Bev | |
|---|---|---|---|
| Chevrolet | 7 | Cruze, Malibu, Malibu Maxx | |
| Volkswagen | 6 | Golf, Beetle, Jetta | |
| Hyundai | 3 | Sonata | |
| GMC | 2 | Yukon Xl 1500 |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
Emissions stations in states with OBD-II testing fail the vehicle while the check engine light is on. Fix any vacuum leak along with the code, since lean running can also leave the catalyst monitor incomplete.
Frequently asked questions
Can a vacuum leak really set a sensor code?
Yes. Extra air entering after the throttle raises manifold pressure at idle, so the MAP sensor reports higher pressure than the PCM's model predicts. The sensor is telling the truth, and replacing it won't make the code go away.
How do I tell a bad sensor from a real engine problem?
Compare the MAP reading with a mechanical vacuum gauge at idle. If both show the same weak vacuum, the engine has a leak, an EGR fault, timing trouble or a restriction; if the gauge looks healthy while MAP doesn't, the sensor or its hose is at fault.
What should MAP read with the engine off?
Exactly the barometric pressure where you are: about 101 kPa near sea level, about 91 kPa at 3,000 feet and about 84 kPa at 5,000 feet, shifting a little with the weather. Anything far outside that before start-up is a sensor issue.
P0106 appeared right after I replaced the MAP sensor. Why?
Check the part number first: sensors for turbo engines cover a wider pressure range and give different voltages. Also make sure the O-ring seated properly and the hose wasn't kinked or left off during installation.