Fault code P1405 – a step-by-step guide to diagnosing and fixing it

Error code P1405 is displayed and the check engine light is on - what does this mean?

The DTC P1405 is recognized by the OBD system if there is a problem with the EGR valve (exhaust gas recirculation valve) or its control circuit. This manufacturer-specific error code mainly occurs in Ford vehicles and indicates a malfunction in the EGR system, which can lead to increased emissions and performance problems.

What can cause this fault code?

• Defective EGR valve
• Blocked EGR channels due to soot deposits
• Damaged vacuum hose system
• Faulty EGR position sensors
• Defective control circuits or cable connections
• Dirty or defective EGR seals
• Problems with the engine control unit (ECM)
• Blocked EGR cooler

What symptoms occur in parallel with fault code P1405?

• Idling problems: Unsteady or fluctuating idling due to faulty exhaust gas recirculation
• Power loss: Reduced engine power, especially at low engine speeds
• Increased fuel consumption: Poorer fuel efficiency due to optimum combustion
• Knocking noises: Metallic knocking noises during acceleration
• Black smoke: Dark exhaust fumes from the exhaust pipe
• Starting problems: Difficult cold starts or prolonged warm-up

How can you fix the problem with error code P1405?

• Repairing EOBD error code P1405 requires a systematic approach to identifying and eliminating the cause.
• Clean or replace the EGR valve: Remove the EGR valve, clean it thoroughly with brake cleaner or, if irreparably damaged, replace it completely to restore proper exhaust gas recirculation function.
• Clean the EGR ducts and cooler: Remove soot deposits from all EGR lines and the cooler, using special EGR cleaners and ensuring that the flow is fully restored.
• Check and replace vacuum hoses: Check all vacuum hoses for cracks, porosity or loose connections and replace damaged hoses with new original parts.
• Calibrate or replace EGR position sensor: Test the position sensor with an OBD diagnostic device, recalibrate if malfunctioning or replace the sensor completely.
• Check electrical connections: Check all plug connections and cables to the EGR system for corrosion, breaks or loose contacts and repair or replace if necessary.
• Carry out an engine control unit update: If there are known software problems, have an ECM update carried out by the dealer or reset the control unit.