Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the part of the car that checks for leaks in the fuel system. It's like a sensor isn't working right, so it can't tell if there's a leak.
The P24B9 code is triggered when the Engine Control Module (ECM) detects a problem with the pressure sensor circuit in the Evaporative Emission Control (EVAP) system's leak detection pump.
The EVAP system prevents fuel vapors from escaping into the atmosphere. The leak detection pump is a component that pressurizes the system to check for leaks. The pressure sensor monitors this process. If the sensor's readings are outside the expected range, the ECM sets the P24B9 code.
• Check Engine Light (CEL) is on
• Possible fuel odor
• Failed emissions test
• Faulty leak detection pump pressure sensor
• Wiring issues or poor electrical connections in the sensor circuit
• Malfunctioning ECM
EVAP: Evaporative Emission Control System
ECM: Engine Control Module
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for the pressure sensor.
• Test the pressure sensor for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the faulty pressure sensor.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regularly inspect and maintain the EVAP system.
• Ensure fuel cap is properly tightened.
• Keep the vehicle's software updated.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if you're not experienced with car repairs.
Check if the vehicle's emissions system is covered under warranty.
This code has become more common as vehicles have become more reliant on sensors for emissions control.
Moderate – While it may not affect immediate drivability, it can lead to increased emissions and fuel odor.
Driving with an emissions-related fault can result in failing emissions tests and may be illegal in some areas.
• Engine running
• Vehicle at operating temperature
The leak detection pump and pressure sensor are typically located near the fuel tank or in the rear of the vehicle.
Q: Can I drive with a P24B9 code?
A: Yes, but it's best to fix it soon to avoid emissions issues.
Q: Will this code affect my gas mileage?
A: It might, as it can cause the system to not work efficiently.
High-End · Full-system diagnostics
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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
Relevant when EVAP diagnosis points toward purge-flow or purge-control faults.
EVAP diagnosis often includes purge-flow and valve-control faults.
Confirm the failed valve and exact fitment before buying parts.
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.