P0409

EGR Sensor A Circuit

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Unstable idle
Loss of engine power
Increased fuel consumption
Check Engine Light Illuminates

Causes

Open or short circuit in wiring harness
EGR sensor malfunction
Contamination or mechanical failure of the EGR valve
Connector problems or contact corrosion

How to Fix

Check the integrity of the EGR sensor wiring harness
Check connectors and contacts for corrosion or damage
Test the EGR sensor to ensure it meets specifications
Replace EGR sensor if necessary
Clean or replace the EGR valve if contamination or mechanical damage is detected

Related codes

P0401 P0402 P0403 P0404