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 computer in your car is having trouble reading the pressure in the first cylinder of the engine. It's like when a thermometer isn't working right and can't tell you the temperature.
The P0395 code indicates a problem with the electrical circuit of the pressure sensor for cylinder 1. The engine control module (ECM) is unable to get accurate pressure readings from this sensor.
The Cylinder 1 Pressure Sensor is responsible for providing the ECM with data on the pressure inside the first cylinder. This information is crucial for the ECM to adjust fuel injection and ignition timing. A fault in the sensor circuit can lead to incorrect readings and engine performance issues.
• Check Engine Light is on
• Poor engine performance
• Increased fuel consumption
• Faulty cylinder 1 pressure sensor
• Damaged wiring or connectors
• ECM failure
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the cylinder 1 pressure sensor for proper operation.
• Replace the faulty pressure sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Socket set
$150 - $400
Moderate
• Vehicle 1
• Vehicle 2
• Vehicle 3
• Regularly inspect engine wiring and connectors.
• Perform routine engine maintenance.
• Use high-quality fuel.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional.
• Avoid driving long distances until the issue is resolved.
Check your vehicle's warranty for coverage on engine sensors.
This code has been associated with sensor failures in certain vehicle models, leading to recalls and service bulletins.
Moderate – It should be addressed soon to prevent further engine issues.
Driving with a faulty pressure sensor can lead to increased emissions and may not meet legal standards.
• Engine at operating temperature
• Vehicle in a safe, stationary position
The cylinder 1 pressure sensor is typically located on or near the engine block, close to cylinder 1.
Q: Can I drive my car with a P0395 code?
A: It's not recommended to drive for long periods with this code, as it can lead to engine performance issues.
Q: How do I reset the Check Engine Light after fixing the issue?
A: Use an OBD-II scanner to clear the code, or disconnect the battery for a few minutes.
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.
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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.
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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.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
View options on Amazon
Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.