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 getting a signal that's too high from a part that checks how well the engine is working. It's like when a microphone is too loud and makes a screeching noise.
The code P1371 indicates that the ionic current signal, which is used to monitor combustion quality in the engine, is higher than expected in Bank 1.
The P1371 code is triggered when the Engine Control Module (ECM) detects a high voltage signal from the ionic current sensor in Bank 1. This sensor is part of the system that monitors combustion by measuring the ionic current in the cylinder during the combustion process. A high signal could indicate an issue with the sensor, wiring, or the ECM itself.
• Check Engine Light illuminated
• Poor engine performance
• Possible misfires
• Faulty ionic current sensor
• Wiring issues such as shorts or open circuits
• Faulty Engine Control Module (ECM)
Ionic Current: A measurement of ionized particles in the combustion chamber used to monitor combustion quality.
ECM: Engine Control Module, the computer that controls engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors to the ionic current sensor.
• Test the ionic current sensor for proper operation.
• Repair or replace the ionic current sensor.
• Fix any damaged wiring or connectors.
• Replace the Engine Control Module if necessary.
• OBD-II scanner
• Multimeter
• Wiring repair tools
$150 - $500
Moderate
• Volvo S60
• Volvo XC90
• Saab 9-3
• Regular maintenance checks
• Ensure proper engine tuning
• Monitor engine performance regularly
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid driving the car aggressively until the issue is resolved.
Check if the vehicle's powertrain warranty covers sensor and ECM issues.
This code is relatively rare and typically associated with specific European car models that use ionic current sensors for combustion monitoring.
Moderate – It is advisable to address this issue soon to avoid potential engine performance problems.
Driving with a malfunctioning engine sensor can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle stationary
The ionic current sensor is typically located near the ignition coils on Bank 1 of the engine.
Q: Can I drive my car with a P1371 code?
A: It's best to have it checked soon, as it can affect engine performance.
Q: What happens if I ignore this code?
A: Ignoring it can lead to poor engine performance and potential damage.
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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.
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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.