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Engine Fault Code P240B

Evaporative Emission System Leak Detection Pump Heater Control Circuit Low

Care Engine Code Reader
The Engine Fault Code P240B refers to an issue with the Evaporative Emission System Leak Detection Pump Heater Control Circuit. This code indicates that the heater circuit for the leak detection pump is experiencing a low voltage or resistance problem. This can prevent the pump from functioning properly, which is crucial for detecting leaks in the evaporative emissions system.

Heres a breakdown of what this means:

1. Evaporative Emission System: This system captures fuel vapors from the gas tank and prevents them from escaping into the atmosphere. It includes components like the charcoal canister and the leak detection pump.

2. Leak Detection Pump: This pump helps to check for leaks in the evaporative system. If its not working correctly, it may not be able to detect leaks, which can lead to increased emissions and potential issues with vehicle inspections.

3. Heater Control Circuit: Some leak detection pumps have a heater to help them operate effectively, especially in colder temperatures. A low voltage or resistance in this circuit can lead to the pump not heating up properly.

Possible Causes:
– Faulty leak detection pump
– Damaged wiring or connectors in the heater circuit
– A blown fuse related to the pump
– Issues with the engine control module (ECM)

Manufacturer Variations:
While P240B generally has the same meaning across different manufacturers, the specific components and systems may vary. Here are some considerations based on different brands:

Porsche: Similar issues may arise, but the diagnostic tools and repair procedures may be specific to Porsche models.
Mini: The code might relate to different components in the evaporative system, given Minis unique design.
Mercedes: Mercedes vehicles may have additional fault codes or specific diagnostic procedures that differ slightly from others.
Audi: Audi models may have variations in the evaporative system setup, which could lead to different underlying issues.
Jaguar: Jaguars luxury systems might include more complex control units that could affect how this code is triggered.
Land Rover: Land Rover vehicles often have more rugged setups, which might lead to different causes for the same code.

What to Do:
If you encounter this code, its best to:
1. Inspect the leak detection pump and its wiring.
2. Check for any blown fuses.
3. Use a diagnostic scanner to see if there are additional codes that could point to related issues.
4. Consider consulting a professional mechanic for a thorough diagnosis if youre unsure.

Addressing this code is important to ensure your vehicle runs efficiently and meets emissions standards.
The Engine Fault Code P240B indicates a problem with the evaporative emission system, specifically related to the leak detection pump heater control circuit being low. This code can be triggered by several issues, and while the basic principles are similar across manufacturers, there can be differences in how each brand handles these components. Here are some common causes:

1. Faulty Leak Detection Pump: The pump itself may be defective, leading to improper operation of the heater circuit.

2. Wiring Issues: Damaged or corroded wiring in the heater control circuit can cause low voltage or no voltage to reach the pump.

3. Bad Connector: A poor connection at the leak detection pump or related components can lead to issues in the circuit.

4. Blown Fuse: A blown fuse related to the evaporative emission system can interrupt power to the pump heater.

5. ECM Issues: The Engine Control Module (ECM) may have a fault that is causing it to incorrectly read the circuit status.

6. Ground Issues: A poor ground connection can affect the operation of the heater circuit, leading to a low signal.

7. Temperature Sensor Fault: If the system includes a temperature sensor that is malfunctioning, it might not allow the heater to operate correctly.

Manufacturer Differences:
Porsche: May have additional sensors or modules in the evaporative emission system that can affect the code.
Mini: The wiring harness may be more compact, leading to potential wear or damage more quickly.
Mercedes: Often has multiple modules that communicate; a fault in one module can affect others.
Audi: May have more complex systems that include additional emissions controls, which could complicate diagnostics.
Jaguar: Known for having unique wiring and connectors, which can lead to specific faults in the circuit.
Land Rover: May have more off-road related features that can affect the emissions system, especially in older models.

When diagnosing this code, it`s essential to check each of these components and consider the specific design and layout of the vehicle`s emissions system.
The Engine Fault Code P240B relates to the evaporative emission system, specifically indicating a problem with the leak detection pump heater control circuit being too low. This can affect vehicles from various manufacturers, including Porsche, Mini, Mercedes, Audi, Jaguar, and Land Rover. Heres how to address this issue:

General Steps to Fix P240B:

1. Check the Fuse:
– Locate the fuse box and check for any blown fuses related to the evaporative emission system. Replace any blown fuses.

2. Inspect the Wiring:
– Look for damaged or corroded wiring leading to the leak detection pump. Repair or replace any damaged wires.

3. Test the Leak Detection Pump:
– Use a multimeter to check the resistance of the leak detection pump heater. If the resistance is outside the manufacturers specifications, the pump may need replacement.

4. Check the Relay:
– If your vehicle has a relay for the leak detection pump, test it. Replace it if its faulty.

5. Inspect the Connector:
– Ensure the electrical connector to the leak detection pump is clean and secure. Corrosion or loose connections can cause low voltage issues.

6. Scan for Additional Codes:
– Use an OBD-II scanner to check for any other related codes. Address any additional codes that may provide more context.

7. Clear the Codes:
– After making repairs, clear the fault codes using an OBD-II scanner and take the vehicle for a test drive to see if the code returns.

Manufacturer-Specific Notes:

Porsche:
– Check for software updates or recalls related to the evaporative emission system. Sometimes, a software glitch can trigger this code.

Mini:
– Mini vehicles may have specific connectors that are prone to corrosion. Make sure to inspect these closely.

Mercedes:
– Mercedes vehicles often have complex wiring harnesses. Ensure that you check for any common issues related to the wiring harness in your specific model.

Audi:
– Audi models may have additional components in the evaporative system. Check the entire system for leaks or blockages.

Jaguar:
– Jaguar vehicles may have unique diagnostic tools; consider using a Jaguar-specific scanner for more accurate diagnostics.

Land Rover:
– Land Rover vehicles can be sensitive to battery voltage. Ensure that the battery is in good condition, as low voltage can affect the entire system.


If youve gone through these steps and the code persists, it may be best to consult a professional mechanic or a dealership, especially for complex issues or if your vehicle is still under warranty. Remember to always refer to the specific service manual for your vehicle model for detailed instructions.
Driving with a P240B code, which indicates a problem with the Evaporative Emission System Leak Detection Pump Heater Control Circuit, is generally not safe in the long run. Heres a breakdown of what this code means and how it can affect your vehicle:

What the Code Means:
– P240B indicates that the control circuit for the heater of the leak detection pump is low. This can mean the pump isnt heating properly, which is crucial for detecting leaks in the evaporative emission system.

Potential Issues:
1. Emissions Problems: The evaporative system helps prevent fuel vapors from escaping into the atmosphere. If its not working correctly, you may fail emissions tests.
2. Fuel Efficiency: A malfunctioning system can lead to poor fuel economy.
3. Check Engine Light: The light will likely stay on, indicating that theres a problem that needs addressing.

Manufacturer Differences:
1. Porsche: Driving may not immediately harm your car, but its best to fix it soon to avoid more extensive damage or emissions issues.
2. Mini: Similar to Porsche, you can drive short distances, but long-term neglect can lead to more severe problems.
3. Mercedes: It may affect performance slightly, but it`s advisable to get it checked to maintain the vehicle`s efficiency and emissions compliance.
4. Audi: Driving with this code can lead to further complications, so its best to address it promptly.
5. Jaguar: You might experience minor performance issues, but its best to repair it to avoid potential damage.
6. Land Rover: While you can drive for a short time, its not recommended to ignore the issue for long.


While you might be able to drive your vehicle for a short time with a P240B code, its not advisable to ignore it. The best course of action is to have it diagnosed and repaired as soon as possible to prevent further damage and ensure your vehicle runs efficiently and meets emissions standards.

OBD Codes Explained

Engine Codes

P is for PowerTrain - Engine and Transmission.

P0 Indicates Generic Powertrain Codes

P0 Codes indicate problems with the powertrain and are common for all vehicles using the OBD-II Standard.

P1 Enhanced Manufacturer Specific Codes

P1 Codes are specific to manufacturers.

Sub-System

The 3rd Digit indicates the Sub-System

1 – Emission Management

2 – Injector Circuit

3 – Ignition

4 – Emission Control

5 – Vehicle Speed and Idle

6 – Computer and Output

7 – Transmission

8 – Transmission

9 – Reserved

0 – Reserved

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