The P240C: Evaporative Emission System Leak Detection Pump Heater Control Circuit High refers to an issue where the control circuit for the heater of the leak detection pump in the evaporative emission system is receiving high voltage. This can lead to ineffective leak detection, increased emissions, and potential failure to pass emissions tests.
P240C – Quick Overview
Code | Information |
---|---|
Meaning | P240C: Evaporative Emission System Leak Detection Pump Heater Control Circuit High |
Is it serious? | Yes, high voltage in this circuit can lead to ineffective leak detection and increased emissions. |
Possible causes | – High voltage in the leak detection pump heater control circuit – Faulty leak detection pump heater – Wiring or connector issues |
How to diagnose? | – Measure voltage in the leak detection pump heater control circuit – Inspect and test the leak detection pump heater and wiring – Check connectors for faults |
P240C Meaning
The P240C: Evaporative Emission System Leak Detection Pump Heater Control Circuit High code indicates that the control circuit responsible for heating the leak detection pump in the vehicle’s evaporative emission system is experiencing higher than normal voltage. The heater ensures that the pump operates efficiently, especially in cold conditions, by preventing condensation and ensuring proper functionality. High voltage in this circuit can cause the heater to malfunction, leading to ineffective leak detection, increased emissions, and potential environmental harm. Additionally, this issue can prevent the vehicle from passing emissions inspections.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to identify any additional related codes that might provide more context to the issue. Additional codes can help pinpoint the exact cause. | OBD-II Scanner |
Measure Voltage in the Leak Detection Pump Heater Control Circuit | Use a multimeter to measure the voltage in the leak detection pump heater control circuit. Compare the readings to the manufacturer’s specifications to determine if the voltage is indeed high. | Multimeter, Wiring Diagram |
Inspect and Test the Leak Detection Pump Heater and Wiring | Visually inspect the leak detection pump heater for any signs of damage or wear. Test the heater’s functionality using a diagnostic tool to ensure it operates correctly. Inspect the wiring for any signs of fraying, corrosion, or shorts that could cause high voltage. | Multimeter, Diagnostic Tool, Visual Inspection Tools |
Check Connectors for Faults | Inspect all connectors related to the leak detection pump heater control circuit for secure connections and signs of corrosion or damage. Clean or replace connectors as necessary to ensure a proper electrical connection. | Multimeter, Connector Cleaning Tools |
Inspect and Repair Wiring Issues | Trace the wiring from the control module to the leak detection pump heater, looking for any breaks, shorts, or areas where the wiring may have been damaged. Repair or replace any faulty sections of wiring to restore proper circuit functionality. | Wiring Repair Tools, Multimeter |
Replace Faulty Leak Detection Pump Heater if Necessary | If the leak detection pump heater is determined to be faulty after testing, remove and replace it with a new or properly functioning unit. Ensure that the replacement heater is compatible with the vehicle’s emission system. | Replacement Leak Detection Pump Heater, Basic Hand Tools |
Clear the Code and Test Drive | After performing the necessary repairs, clear the P240C code using an OBD-II scanner. Take the vehicle for a test drive to ensure that the issue has been resolved and the code does not reappear. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | After the test drive, use the OBD-II scanner again to verify that the P240C code has been cleared. If the code returns, further diagnosis may be required to identify and fix underlying issues. | OBD-II Scanner |

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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)