Code
P1450
PONTIAC
P — Powertrain
Barometric Pressure Sensor Circuit
AI status
Completed
Completed
100%
Causes
- Failed barometric pressure (BARO) sensor
- Open or shorted sensor signal, reference, or ground wiring
- Corroded/loose sensor connector or pins
- Water or physical damage to sensor
- Incorrect reference voltage (ECM power/ground issue)
- Intermittent ECU/PCM internal fault or software anomaly
Symptoms
- Malfunction Indicator Lamp (MIL/CEL) illuminated
- Hard starting or long cranking in some conditions
- Rough idle or hesitation under load
- Poor fuel economy and incorrect fuel trims
- Possible failed emissions test / reduced driveability
- Barometric readings mismatch on scan tool vs. ambient
What to check
- Read and record freeze frame and all pending/related codes
- Check battery voltage and engine grounds; ensure stable 12 V
- Visual inspection of BARO sensor, connector and wiring for damage/corrosion
- Use a scan tool to monitor BARO sensor value and compare to actual ambient pressure
- Unplug/replug connectors to check for intermittent faults (with ignition off)
- Wiggle-test wiring while monitoring signal for intermittent changes
Signal parameters
- Sensor supply/reference: typically 5.0 V (some systems use 3.3 V) — verify manufacturer spec
- Sensor output: commonly in the 0.5–4.5 V range corresponding to low–high barometric pressure
- At normal ambient pressure (sea level ~1013 hPa) output should be within manufacturer expected range — compare to scan tool reading
- Ground continuity: low resistance to chassis/ECM ground
- Signal behavior: voltage should change predictably with altitude/pressure changes (voltage drops as pressure falls)
Diagnostic algorithm
- Retrieve freeze frame data and note any related codes (MAP, IAT, EVAP, ECM).
- Visually inspect BARO sensor and connector for damage, corrosion, water intrusion or oil contamination.
- With key ON (engine OFF) backprobe the sensor: verify reference voltage (5V or 3.3V per spec), good ground, and that the signal line has a steady voltage within expected range.
- Compare BARO sensor reading from a scan tool to a known ambient barometric pressure (phone/weather station or local airport). Values should match closely; large differences indicate sensor or wiring fault.
- If signal is out of range, test continuity and resistance of wiring to the ECM. Repair any opens/shorts and inspect harness for chafing.
- If wiring and connector are good, replace the BARO sensor and clear codes; retest drive cycle.
- If replacement sensor does not correct the issue, investigate ECM input and reference circuits; consult wiring diagram and consider ECM bench testing or replacement as a last resort.
- After repairs, clear codes and verify freeze frame and live data over a complete drive cycle to ensure fault does not return.
Likely causes
- Broken or chafed signal wire between BARO sensor and ECM
- Low battery or poor ground causing bad sensor reference
- Sensor contaminated by oil/water or mechanically damaged
- Connector corrosion or bent pins at sensor or ECU
- Aftermarket modification or incorrect replacement sensor
- Rare: ECM fault affecting sensor reference or input
Fault status
Status
Barometric Pressure Sensor Circuit — stored when the ECM detects a missing, out-of-range, or implausible BARO sensor signal or related circuit fault.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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