P2385 – Turbocharger Boost Pressure Sensor A/B High

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: General | Location: Designator A

Definition source: SAE J2012/J2012DA (industry standard)

P2385 is a powertrain diagnostic trouble code that indicates the control module has detected a high electrical input condition involving the turbocharger boost pressure sensor A/B signals. “High” refers to the sensor circuit reading higher than expected, which is typically caused by an electrical issue (such as a short to voltage, an open ground, or a reference/signal problem) rather than confirming a mechanical turbocharger fault. The exact sensor arrangement (single sensor with dual channels, two sensors, or correlated inputs) varies by vehicle, so always verify circuit routing, pinouts, and test criteria in the correct service information.

What Does P2385 Mean?

P2385 means the vehicle has detected a Turbocharger Boost Pressure Sensor A/B High condition. Based on the official definition, the fault is centered on the boost pressure sensing circuits identified as A and B, with the module determining the input is electrically “high” compared to its expected operating range. Under SAE J2012 DTC structure conventions, this type of wording indicates an electrical high-input condition (for example, a signal circuit shorted to a voltage source, an open or poor ground path, a skewed reference feed, or a connector/wiring fault) that must be confirmed with circuit testing and scan-tool data.

Quick Reference

• System: Powertrain
• Official meaning: Turbocharger Boost Pressure Sensor A/B High
• Standard: ISO/SAE controlled
• Fault type: Circuit High
• Severity: MIL illumination is possible, and boost control may be limited or incorrect, which can cause reduced power and unstable drivability depending on operating conditions.

Symptoms

• MIL/Check engine: Warning light illuminated and the code stored as current or pending.
• Reduced power: Torque limitation or protective strategy that reduces acceleration, especially under load.
• Boost control changes: Noticeably weak boost response or inconsistent boost behavior when requesting power.
• Hesitation: Momentary stumble or delay during throttle transitions as boost control is recalculated.
• Unstable shifting: Transmission shift timing/feel changes due to altered engine torque reporting (varies by vehicle).
• Fuel economy change: Increased consumption if the control strategy compensates for an implausible high boost-pressure signal.
• Additional codes: Related sensor reference/ground, boost control, or correlation codes may also be present.

Common Causes

• Connector issues: Loose fit, bent pins, corrosion, moisture intrusion, or damaged seals at the boost pressure sensor A and/or B connectors.
• Signal circuit short-to-power: Sensor signal wire(s) contacting a voltage feed, pulling the reported signal high.
• Reference circuit fault: Reference supply circuit driven high due to harness damage, incorrect backfeeding, or internal module fault (varies by vehicle design).
• Ground circuit open/high resistance: Broken ground wire, poor splice, or terminal fretting causing the sensor output to read high relative to ground.
• Harness damage: Chafing, pinched wiring, heat damage near turbo/charge-air components, or contact with sharp brackets causing shorts or opens.
• Sensor fault: Internal failure of boost pressure sensor A and/or B producing a biased high output.
• Incorrect part/installation: Wrong sensor type, mis-pinned connector, or aftermarket pigtail wiring errors leading to a high input.
• Control module input issue: Rare PCM/ECM input circuit fault or connector problem causing an interpreted high signal.

Diagnosis Steps

Tools typically needed include a scan tool capable of viewing live data and freeze-frame, a digital multimeter, and basic backprobing leads. Depending on access, a wiring diagram and connector pinout from service information are essential to identify sensor A vs. sensor B circuits and their reference/ground paths. If available, a lab scope can help confirm a steady high signal and detect intermittents during harness movement.

1. Confirm the code and capture data: Verify P2385 is present. Record freeze-frame and note when it sets (key on, idle, under load). Check for additional related DTCs (reference supply, sensor correlation, or module power/ground codes) and address them in a logical order per service info.
2. Identify sensors A and B on this vehicle: Using service information, confirm which two boost pressure sensors are designated A and B (varies by vehicle). Document connector pin functions (signal, reference, ground) for each.
3. Quick visual inspection: With ignition off, inspect both sensor connectors and harness routing. Look for rubbing, melted insulation, pinched sections, oil saturation, or recent repairs. Pay special attention to areas near hot components and where the harness is clipped to brackets.
4. Connector and terminal checks: Disconnect sensor A and sensor B connectors. Inspect for pushed-out terminals, spread pins, corrosion, water, and damaged seals. Verify terminals have proper tension (no loose male/female fit) and that any CPA/locks are intact.
5. Key-on signal plausibility check (unplug test): With key on and sensors disconnected (as appropriate for the design), observe the scan tool PID(s) for boost pressure sensor A and B. A true circuit-high condition may remain high or behave abnormally. Compare A vs. B behavior; large differences can help isolate which circuit is affected. Follow service info for expected behavior when unplugged.
6. Check reference supply integrity: With key on, measure the sensor reference supply at each connector against chassis ground, then verify it is stable and not elevated beyond the specified range in service information. If the reference appears incorrect, isolate by unplugging other sensors sharing that reference circuit (varies by vehicle) to see if the line recovers.
7. Voltage-drop test the ground circuit: Load the ground circuit (using an approved method per service info) and perform a voltage-drop test between sensor ground pin and battery negative/known good ground. Excessive drop indicates high resistance (poor splice, corroded terminal, broken strands) that can make the sensor signal read high.
8. Check for short-to-power on the signal circuit: With ignition off and connectors unplugged, test for continuity/short between each sensor signal wire and power feeds in the harness (and between signal and reference if applicable). Any continuity to power where it should not exist indicates insulation damage or miswiring.
9. Harness isolation and wiggle test: Reconnect components as needed and monitor live data for sensor A and B while gently moving the harness, especially near connectors, clips, and known rub points. If the reading spikes high or the code resets during movement, focus on that segment for an intermittent short/open or terminal fretting.
10. Sensor substitution/verification: If circuits (reference, ground, signal) test good and the signal remains high, verify the sensor is the correct type and correctly pinned. Replace only the sensor identified by testing as biased high, then recheck live data and run the appropriate drive cycle to confirm the repair.
11. Module-side verification: If the harness and sensor test good but the scan tool still reports a high input, test the circuit at the control module connector (per service info) to confirm whether the high signal is present at the module pin. If the signal is normal at the sensor but high at the module, suspect harness damage between; if high at the module with the circuit isolated, consider a module connector/pin issue or internal input fault (rare).

Professional tip: When chasing a “high input” fault, prioritize proving the integrity of sensor ground and ruling out signal short-to-power before replacing parts. A marginal ground or a harness rub-through can create a consistently high reading that looks like a bad sensor. Log live data during a controlled wiggle test and correlate any spikes with specific harness movement points for faster fault localization.

Possible Fixes & Repair Costs

Repair costs can vary widely because the root cause of a “high input” boost pressure sensor signal may be wiring-related, sensor-related, or control-module related, and labor depends on access and the diagnostic time required. Confirm the failure with testing before replacing parts.

• Repair or replace damaged wiring between the boost pressure sensors and the control module, focusing on short-to-power faults and rubbed-through insulation
• Clean, dry, and secure sensor and module connectors; correct poor pin fit, corrosion, or water intrusion found during inspection
• Restore proper sensor ground integrity by repairing ground circuits and verifying low resistance under load (voltage-drop tested)
• Correct reference-voltage issues by isolating the affected reference circuit, unplugging loads one at a time to locate the branch pulling the circuit high
• Replace the turbocharger boost pressure sensor identified as biased high after confirming power, ground, and signal integrity
• Repair intake/charge-air sensor plumbing or mounting only if it is proven to be causing an electrical high signal condition (for example, strain on wiring/connectors)
• Perform control-module connector repairs or terminal replacement if testing confirms intermittent high input caused by terminal tension or fretting
• Relearn/initialization procedures and a verification drive cycle after repairs, as required by service information

Can I Still Drive With P2385?

Driving may be possible, but it is not recommended if the vehicle enters reduced-power mode, surges, hesitates, or shows unstable acceleration, since an erroneously high boost pressure signal can lead to protective torque limiting and unpredictable drivability. Do not drive if there is stalling, no-start, severe misfire symptoms, or any warning indicating reduced braking or steering assistance; tow it and diagnose the electrical high input condition first.

What Happens If You Ignore P2385?

Ignoring P2385 can result in recurring warning lights, continued reduced-power operation, poor throttle response, and inconsistent turbocharger control strategies that may increase exhaust temperatures and fuel consumption. If the high signal is caused by a wiring fault that worsens (such as chafing), the condition can become intermittent-to-constant and may trigger additional sensor or reference-circuit DTCs.

Last updated: February 16, 2026

Vehicles Commonly Affected by P2385

• Vehicles equipped with a turbocharger or supercharger that uses one or more boost pressure sensors
• Applications with dual boost pressure sensors (labeled A/B) for redundancy or plausibility monitoring
• Engines with electronically controlled boost via actuators/solenoids managed by the powertrain control module
• Vehicles with complex shared 5-volt reference circuits powering multiple sensors
• Platforms with tight engine-bay packaging where harnesses can chafe near hot or sharp components
• Vehicles frequently operated in wet, salty, or high-humidity environments that accelerate connector corrosion
• High-mileage vehicles where terminal tension, pin fretting, or harness fatigue becomes more likely
• Vehicles that have had recent engine work where connectors may be left partially seated or wiring rerouted

For best results, confirm the exact sensor labeling (A versus B), connector pinout, and the shared reference/ground architecture in service information before testing or replacing any components.