P0407

Symptoms

• Check Engine light is on
• Reduced fuel efficiency
• Detonation under load
• Unstable idle
• Increased exhaust toxicity
• Possible emergency operation of the engine

Causes

• EGR sensor wiring short to ground
• Sensor power supply circuit open
• Faulty EGR valve position sensor B
• Oxidation or damage to the sensor connector
• EGR valve dirty or stuck
• ECU malfunction (extremely rare)

How to Fix

1. Connect the diagnostic scanner and read all active codes
2. Check the sensor supply voltage (usually 5 V from the ECU)
3. Check the sensor ground wire for integrity
4. Inspect the connector and wiring harness for damage.
5. Measure the sensor resistance and compare with the norm
6. Replace EGR sensor B if its malfunction is confirmed
7. Reset the error code and take a test drive

Related codes

Error P0407 by Vehicle Brand