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 has detected a problem with the sensor that helps control how much air goes into the engine. It's like a broken remote control for a toy car that can't tell the car to go faster or slower properly.
The P1591 code indicates that the throttle position sensor 2 is reporting a voltage that is too high, which suggests a potential issue with the sensor or its circuit.
The throttle position sensor (TPS) is a critical component that monitors the position of the throttle valve in the engine. The P1591 code is triggered when the Engine Control Module (ECM) detects a higher than expected voltage from the throttle valve 2 potentiometer 1/2 circuit. This could be due to a malfunctioning sensor, wiring issues, or a faulty ECM.
• Check Engine Light is on
• Poor engine performance
• Hesitation or stalling during acceleration
• Faulty throttle position sensor
• Wiring issues such as shorts or open circuits
• Defective ECM
Throttle Position Sensor: A sensor that monitors the position of the throttle valve.
ECM: Engine Control Module, the computer that controls engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the throttle position sensor with a multimeter.
• Replace the throttle position sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Screwdriver set
$150 - $400
Moderate
• Volkswagen Jetta
• Audi A4
• BMW 3 Series
• Regularly inspect and clean throttle body and sensors.
• Ensure wiring and connectors are free from corrosion.
• Perform routine maintenance checks.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Avoid driving aggressively until the issue is resolved.
Check with your vehicle manufacturer as some throttle components may be covered under warranty.
The P1591 code has been more prevalent in vehicles with electronic throttle control systems introduced in the late 1990s.
Moderate – It should be addressed soon to prevent further engine performance issues.
Driving with a malfunctioning throttle position sensor can be dangerous and may lead to unexpected vehicle behavior.
• Engine at operating temperature
• Vehicle in park or neutral
The throttle position sensor is typically located on the throttle body, which is connected to the intake manifold.
Q: Can I drive with a P1591 code?
A: It's not recommended to drive for long periods with this code as it can affect engine performance and safety.
Q: How can I reset the Check Engine Light?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, the light should stay off.
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