Manifold Absolute Pressure Sensor B Circuit Intermittent/Erratic
The MAP B signal drops out or jumps intermittently. Loose connector or noisy ground reference. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Affected components
- Map sensor b
- Wiring harness
- Ecm
Common causes
- High likelihood: Sensor connector not seated
- Medium likelihood: Noisy ground reference
- Low likelihood: Connector with intermittent contact under vibration
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.