Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car has a system that checks for leaks in the fuel system to make sure gas fumes aren't escaping. This code means there's a problem with the part that checks for leaks.
The P1406 code indicates a malfunction within the Evaporative Emission Control System's leak detection module, which is responsible for detecting fuel vapor leaks.
The EVAP system is designed to capture and store fuel vapors from the fuel tank and prevent them from escaping into the atmosphere. The leak detection module monitors the system for leaks. If it detects an internal error, the P1406 code is triggered.
• Check Engine Light is on
• Failed emissions test
• Fuel odor around the vehicle
• Faulty leak detection pump
• Damaged or corroded wiring or connectors
• Malfunctioning EVAP pressure sensor
EVAP: Evaporative Emission Control System
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the leak detection pump and EVAP pressure sensor for proper operation.
• Replace the faulty leak detection pump.
• Repair or replace damaged wiring or connectors.
• Replace the EVAP pressure sensor if faulty.
• OBD-II scanner
• Multimeter
• Vacuum pump
$150 - $500
Moderate
• Chevrolet Silverado
• Ford F-150
• Toyota Camry
• Regularly inspect EVAP system components.
• Ensure fuel cap is properly tightened.
• Use quality fuel to prevent system contamination.
Sensor Issue
• Have the vehicle inspected by a professional.
• Avoid overfilling the fuel tank.
• Check for fuel odors regularly.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
The P1406 code has been associated with vehicles that have aging EVAP systems or are operated in areas with high humidity or salt exposure.
Moderate – While the vehicle may still operate normally, addressing the issue is important to pass emissions tests and prevent fuel vapor leaks.
Ignoring this code may result in failing emissions tests and could contribute to environmental pollution.
• Engine at operating temperature
• Vehicle parked on a level surface
The EVAP leak detection module is typically located near the fuel tank or within the engine compartment.
Q: Can I drive with a P1406 code?
A: Yes, but it's recommended to fix the issue to pass emissions tests and prevent fuel vapor leaks.
Q: Will a P1406 code cause my car to fail an emissions test?
A: Yes, a P1406 code can cause your car to fail an emissions test due to potential fuel vapor leaks.
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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.