🚨 Diagnostic Profile
Vehicle Make: ACURA
Technical Description: BARO Circuit High Input
This code indicates that the Powertrain Control Module (PCM) has detected a voltage signal from the Barometric Pressure (BARO) sensor that is higher than the expected calibrated range. The BARO sensor measures atmospheric pressure to help the PCM adjust fuel trim and ignition timing based on altitude. A ‘High Input’ fault typically points to a wiring short to voltage, a failing sensor, or a corrupted internal PCM reference signal.
🚨 Repair Difficulty Tier
Difficulty Rating: [Intermediate]
This repair requires the use of a professional-grade OBD-II scanning tool capable of reading live sensor data (PIDs) and a digital multimeter to test wiring integrity. While the physical replacement of the sensor (if integrated into the MAP sensor housing) is straightforward, accurately diagnosing whether the fault lies in the wiring harness, the sensor itself, or the PCM requires intermediate electrical diagnostic knowledge.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Begin by visually inspecting the wiring harness connected to the MAP/BARO sensor, typically located on the intake manifold or firewall bulkhead. Look for chafed, pinched, or corroded wires, specifically checking for a short circuit where the signal wire may be rubbing against the 5V reference wire. Also inspect the electrical connector for pushed-out pins or corrosion.
Step 2: Diagnostic Verification
Connect a scan tool and monitor the BARO/MAP live PID. At sea level, the reading should typically hover around 29-31 in-Hg (or ~100-103 kPa) with the key on, engine off. If the multimeter reads close to 5V or the scan tool reads a maxed-out value regardless of engine load, this confirms a ‘High Input’ short. Back-probe the sensor connector with a multimeter to check for a steady 5V reference voltage and a stable ground; if the signal wire reads full reference voltage without fluctuation, the sensor or wiring is confirmed faulty.
Step 3: Resolution & Reset Process
If wiring is intact and voltages align with sensor failure, replace the BARO/MAP sensor unit. After installation, clear the Diagnostic Trouble Codes (DTCs) using the scan tool and perform an idle relearn procedure if specified by the manufacturer. Road test the vehicle across varying RPM ranges to ensure the new sensor data stream remains stable and the Check Engine Light does not return.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: BARO/MAP Sensor, Electrical Contact Cleaner, Wiring Harness Repair Kit (if applicable), OBD-II Diagnostic Scanner.
Average Component Price: $45 – $120 (Sensor Only)
Estimated Labor Hours: 0.5 – 1.5 hours (Diagnosis and Replacement)