What Does P1406 Mean?
The DPFE sensor downstream hose circuit has detected an abnormal signal. This indicates a problem with the downstream pressure measurement side of the EGR monitoring system.
Common Causes
35%
DPFE sensor downstream hose disconnected, cracked, or blocked
30%
DPFE sensor failure or internal malfunction
20%
Carbon buildup blocking EGR passages or sensor ports
10%
Wiring harness damage or poor connector at DPFE sensor
5%
PCM internal fault in DPFE sensor circuit driver
Diagnostic Steps
1
Step 1: Visually inspect DPFE sensor downstream hose for disconnection, cracks, or blockage
2
Step 2: Check electrical connector at DPFE sensor for corrosion, damage, or proper seating
3
Step 3: Test DPFE sensor voltage signal at sensor connector using multimeter during engine operation
4
Step 4: Inspect EGR tube and passages for carbon deposits restricting pressure sensing
5
Step 5: Replace DPFE sensor if hoses and connections are intact, then clear codes and retest
Estimated Repair Cost
$100 - $350
Parts + labor, varies by vehicle and location
The DPFE sensor downstream hose circuit has detected an abnormal signal. This indicates a problem with the downstream pressure measurement side of the EGR monitoring system.
The most common cause of P1406 (Differential Pressure Feedback Electronic Sensor circuit Downstream Hose) is: DPFE sensor downstream hose disconnected, cracked, or blocked
Typical repair costs for P1406 range from $100 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but emissions will increase and fuel economy may decrease. Address within a week to prevent catalytic converter damage.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1406 to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control System (EGR)
Difficulty
Type
Manufacturer
Recommended Tools
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