P0109 - Manifold Absolute Pressure/Barometric Pressure Circuit Circuit Intermittent

The MAP or BARO sensor signal is cutting in and out intermittently.

Code Overview

The MAP or BARO sensor signal is cutting in and out intermittently.

Common Causes

• Failing MAP or BARO sensor
• Damaged wiring or loose connector at the sensor
• Intermittent open or short in the circuit
• Loose vacuum source or sensor-port issue on applicable systems

Symptoms

• Intermittent hesitation or surge
• Unstable idle quality
• MAP or BARO readings that drop out unexpectedly

Diagnostic Steps

1. Wiggle-test the MAP or BARO connector and harness while watching scan data
2. Verify reference voltage, ground, and signal integrity at the sensor
3. Compare scan data to a realistic barometric or load-related reading
4. Inspect the vacuum hose or sensor port if the system uses one

Repair Difficulty

Moderate

General difficulty estimate for the most common repair path.

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

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Next Steps

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