P0106

Code

Generic P — Powertrain

Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 67 EN: 121 RU: 181

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Page language: EN

Causes

Damaged or failed MAP/BARO sensor
Open, shorted or corroded wiring or connector (signal, reference, ground)
Blocked or contaminated sensor port or vacuum line
Intake manifold vacuum leak or restriction
Incorrect reference voltage (5V) or poor ground from ECM
Intermittent connector contact or water ingress

Symptoms

Check Engine Light (MIL) illuminated; code P0106 stored
Rough idle, stalling or surging
Poor acceleration, hesitation or reduced power
Hard starting or increased cranking time
Reduced fuel economy and higher emissions
Inconsistent idle speed or unpredictable throttle response

What to check

Read and record freeze-frame and live data (MAP, BARO, RPM, throttle position, intake air temp) with scan tool
Visually inspect MAP/BARO sensor, connector, wiring harness and vacuum line for damage, corrosion or disconnection
Check for blocked sensor port or contaminated vacuum hose
Verify battery voltage and ground integrity at battery and engine ground
Confirm ECM provides correct reference voltage (typically 5V) at sensor connector
Backprobe sensor signal and measure voltage at key conditions (KOEO, idle, WOT)

Signal parameters

Typical MAP/BARO reference: 5.0 V supply (±0.25 V) from ECU
Typical signal range: ~0.5–4.5 V (low voltage = high vacuum/low absolute pressure; high voltage = near atmospheric pressure)
Key ON / Engine OFF (atmospheric): signal near high end (~3.5–4.5 V) depending on sensor
Idle (closed throttle / vacuum): lower voltage (~0.5–2.0 V) reflecting intake vacuum
Wide-open throttle (near atmospheric): signal should rise toward high end (~3.5–4.5 V)
Signal should change smoothly with applied/removed vacuum (no sudden jumps or dropouts)

Diagnostic algorithm

Retrieve freeze-frame data and confirm P0106 is current/repeat. Note engine conditions when set (RPM, temperature, throttle position).
Visually inspect MAP/BARO sensor, port and vacuum hose. Clear any debris and ensure port is open.
Check connector and wiring for damage, corrosion, bent pins, or moisture. Secure connector and repair visible damage.
With ignition ON (engine OFF) verify reference voltage at sensor harness (≈5V). If absent, check fuses, wiring to ECM and ECM power supply.
Backprobe signal wire and measure voltage with engine OFF (atmospheric). It should be near the high end of expected range. Start engine and observe signal — it should drop at idle (vacuum) and rise with throttle. Use a hand vacuum pump on sensor/vacuum line to confirm smooth, proportional voltage change.
If reference and ground are good but signal abnormal or intermittent, check wiring continuity and resistance to ECM for shorts to 5V or ground. Wiggle test harness while monitoring signal for intermittent faults.
Inspect for intake manifold vacuum leaks (smoke test or pressure test). Repair any leaks and retest.
If wiring and intake are good, swap with a known-good MAP sensor (or replace sensor) and clear codes. Road test and monitor data.
If problem persists after sensor replacement and wiring verified, consider ECM fault — confirm with dealer-level diagnostics or replace ECM as last resort.

Likely causes

Failed MAP sensor diaphragm or internal electronics
Wiring shorted to battery or ground, or high resistance in signal/ground circuit
Blocked MAP sensor port (carbon/debris) or kinked vacuum hose
Loose/poor sensor connector pins or corrosion
Faulty ECM or blown sensor supply fuse (less common)

Fault status

⚠️ Status

MAP/BARO sensor circuit range/performance fault — the MAP or BARO signal is outside expected parameters or does not correlate to engine conditions. Investigation of sensor, wiring, vacuum system and ECM required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours