Code
P1107
INFINITI
P — Powertrain
BARO Circuit Low Input
Views:
UK: 40
EN: 57
RU: 43
AI status
Completed
Completed
100%
Causes
- Faulty BARO sensor
- Open or shorted signal wiring (short to ground)
- Poor or corroded connector pins at sensor or ECM
- Blocked/drained sensor vent (if applicable) or plugged port
- Loss of reference voltage (5V) or poor ground
- Intermittent wiring damage (broken strands)
Symptoms
- Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
- Poor idle quality or stalling at idle
- Reduced engine performance or hesitation
- Hard cold start or poor drivability under load
- Lower fuel economy or incorrect fuel trim values
- Possible limp-home mode (on some vehicles)
What to check
- Read freeze frame data and active/recorded fault details with a scan tool
- Monitor BARO sensor value (kPa or inHg) with key ON engine OFF and compare to ambient barometric pressure
- Compare BARO reading to MAP sensor reading (engine off) — readings should be similar with ignition on and engine off
- Check for stored related codes (MAP/IAT/MAF) that may help isolate the circuit
- Visually inspect wiring and connectors for damage, corrosion, rodent chew, or loose pins
- Backprobe sensor harness: measure reference voltage (typical 5 V), signal voltage, and ground continuity
Signal parameters
- Typical reference voltage: ~5.0 V (key ON)
- Typical signal output at sea level: ~1.0–4.5 V (sensor dependent)
- Typical ambient pressure: ~98–105 kPa (sea level ≈ 101 kPa)
- Code often set when signal < ~0.5 V (low input) or signal out of expected range for calibration
Diagnostic algorithm
- Retrieve freeze frame and live data. Confirm P1107 is current or historic and note operating conditions when stored.
- With ignition ON (engine OFF) record BARO sensor voltage and kPa reading using a scan tool. Compare to a known ambient barometric pressure (local weather station or handheld barometer).
- Compare BARO value to MAP sensor value (key ON engine OFF). They should be close; large differences indicate sensor or wiring issue.
- Inspect harness and connector at BARO sensor. Repair any damaged wires, pins, or corrosion. Make sure connector is fully seated.
- Backprobe sensor: verify 5 V reference present, good ground (
- If signal is very low or zero with good 5 V and ground, disconnect sensor and measure resistance or bench-test sensor per service manual. Replace sensor if out of spec.
- If sensor bench test is good, check continuity and for shorts between signal and ground/5 V to the ECM. Repair wiring as needed. Use wiggle tests to detect intermittent faults.
- If wiring and sensor are good but low signal persists at ECM pin, suspect ECM input fault; confirm with vehicle-specific service information before ECM replacement.
- Clear codes and perform road test or key cycles to confirm repair. Re-scan for recurrence.
- Check for software updates or technical service bulletins (TSBs) related to BARO or ECM calibration for the specific Infiniti model.
Likely causes
- Damaged or contaminated BARO sensor
- Signal circuit shorted to ground or open
- Connector corrosion or loose terminal at sensor or ECM
- Missing/low 5 V reference or bad ground at sensor
- Blocked sensor vent or plugged intake fitting
Fault status
Status
ECM detected BARO sensor circuit low input — measured signal below expected range.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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