Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble understanding the air pressure outside, which can affect how the engine runs.
The vehicle's engine control module (ECM) is receiving an implausible signal from the barometric pressure sensor, which is used to measure atmospheric pressure.
The barometric pressure sensor provides data to the ECM to help adjust the air-fuel mixture for optimal engine performance. If the sensor's signal is out of the expected range during startup, the ECM will log a P1171 code.
• Check Engine Light is on
• Poor engine performance
• Increased fuel consumption
• Faulty barometric pressure sensor
• Wiring issues or poor electrical connections
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the barometric pressure sensor and its wiring for damage.
• Test the sensor's output with a multimeter.
• Replace the barometric pressure sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Volkswagen Jetta
• Audi A4
• Skoda Octavia
• Regularly inspect sensor connections.
• Keep the engine bay clean to prevent dirt buildup.
• Perform regular vehicle maintenance.
Sensor Issue
• Have the vehicle inspected by a professional.
• Avoid driving in extreme weather conditions until fixed.
Check if the vehicle is still under warranty for emissions-related components.
This code has been reported in vehicles with faulty or aging sensors, especially in older models.
Moderate – Addressing this issue promptly can prevent further engine performance problems.
Driving with a faulty sensor may lead to increased emissions, which could be illegal in some areas.
• Vehicle is at startup
• Normal atmospheric conditions
The barometric pressure sensor is typically located near the intake manifold or integrated into the ECM.
Q: Can I drive with a P1171 code?
A: It's possible to drive, but it's not recommended as it can affect engine performance and fuel efficiency.
Q: How do I reset the P1171 code?
A: After repairs, use an OBD-II scanner to clear the code, but ensure the issue is fixed to prevent it from returning.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.