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 fuel leaks. It's like a sensor that isn't getting enough power to work properly.
The code P240B indicates that the engine control module (ECM) has detected a low voltage condition in the control circuit for the EVAP system's leak detection pump heater.
The EVAP (Evaporative Emission Control) system prevents fuel vapors from escaping into the atmosphere. The leak detection pump is part of this system and helps check for leaks. The heater in the pump is controlled by the ECM, and if the control circuit has low voltage, it may not function correctly, leading to this error code.
• Check Engine Light is on
• Failed emissions test
• Possible fuel smell
• Faulty EVAP leak detection pump heater
• Wiring issues such as shorts or open circuits
• Faulty ECM or poor connection to the ECM
EVAP: Evaporative Emission Control
ECM: Engine Control Module
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the leak detection pump heater for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the EVAP leak detection pump heater if faulty.
• Check and repair ECM connections if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Toyota Camry
• Ford Focus
• Honda Accord
• Regularly inspect and maintain the EVAP system.
• Ensure all electrical connections are secure and clean.
• Use quality fuel to prevent system contamination.
Sensor Issue
• Have the vehicle inspected by a professional mechanic.
• Avoid driving with a persistent Check Engine Light.
• Keep up with regular vehicle maintenance.
Check with your vehicle manufacturer for warranty coverage on emissions-related components.
This code has been reported in vehicles with aging EVAP systems or those exposed to harsh environmental conditions.
Moderate – It should be addressed soon to prevent potential emissions issues.
Driving with a malfunctioning EVAP system may lead to increased emissions and potential fines in areas with strict emissions laws.
• Vehicle at operating temperature
• EVAP system readiness
The EVAP leak detection pump is typically located near the fuel tank or in the rear of the vehicle.
Q: What does the EVAP system do?
A: The EVAP system captures fuel vapors from the fuel tank and prevents them from escaping into the atmosphere.
Q: Can I drive with a P240B code?
A: While the car may still be drivable, it's best to address the issue promptly to avoid emissions problems.
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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.