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Home/DTC Codes/Lincoln/MKX/2018-2018 2.7L V6 EcoBoost/P1409
P1409

EGR Vacuum Regulator Solenoid Circuit Malfunction

2018-2018 Lincoln MKX 2.7L V6 EcoBoost

Moderate SeverityPowertrain

The 2018 Lincoln MKX is equipped with a 2.7L V6 turbocharged gasoline engine. Below you'll find detailed p1409 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.

Description

The EGR Vacuum Regulator (EVR) solenoid circuit has a malfunction. This solenoid controls vacuum to the EGR valve. When it fails, EGR valve operation is impaired.

Symptoms

  • Check Engine Light
  • EGR valve stuck open or closed
  • Rough idle (if stuck open)
  • Knocking/pinging (if stuck closed)
  • Failed emissions

Common Causes

  • Faulty EVR solenoid
  • Wiring issue to EVR solenoid
  • Clogged vacuum lines to EGR valve
  • PCM driver failure

Diagnostic Steps

  1. Test EVR solenoid resistance (typically 26-40 ohms)
  2. Check wiring and connector
  3. Inspect vacuum lines
  4. Command solenoid with scan tool and verify operation

Repair Notes

Replace EVR solenoid if faulty. Repair vacuum lines. Check wiring.

Related Codes

P0401EGR Flow Insufficient DetectedP0402EGR Flow Excessive DetectedP1400Sub-Throttle Position SensorP1400Sub-Throttle Position SensorP1400EGR System Monitor MalfunctionP1400EGR Output Stage MalfunctionP1400DPFE Sensor Circuit Low InputP1400EGR System Monitor MalfunctionP1400EGR System Monitor MalfunctionP1400EGRC Solenoid ValveP1400Fuel Tank Pressure Control Solenoid LowP1400EGRC Solenoid ValveP1400DPFE Sensor Circuit Low InputP1400Sub-Throttle Position SensorP1400DPFE Sensor Circuit Low InputP1400DPFE Sensor Circuit Low InputP1401DPFE Sensor Circuit High InputP1401Sub-Throttle Position Sensor Range/PerformanceP1401EGR Temperature SensorP1401Sub-Throttle Position Sensor Range/PerformanceP1401EGR Temperature SensorP1401Sub-Throttle Position Sensor Range/PerformanceP1401DPFE Sensor Circuit High InputP1401DPFE Sensor Circuit High InputP1401DPFE Sensor Circuit High Input

Other Powertrain Codes

P1409 on Other Vehicles

Lincoln Aviator

2003-2003 4.6L V8 DOHC

Lincoln Aviator

2004-2004 4.6L V8 DOHC

Lincoln Aviator

2005-2005 4.6L V8 DOHC

Lincoln Aviator

2020-2020 3.0L Twin-Turbo V6

Lincoln Aviator

2020-2020 3.0L V6 Twin Turbo

Lincoln Aviator

2020-2020 3.0L V6 Twin Turbo Hybrid

Lincoln Aviator

2021-2021 3.0L Twin-Turbo V6

Lincoln Aviator

2021-2021 3.0L V6 Twin Turbo

Common Questions

What does code P1409 mean on a 2018-2018 Lincoln MKX?

P1409 stands for "EGR Vacuum Regulator Solenoid Circuit Malfunction". The EGR Vacuum Regulator (EVR) solenoid circuit has a malfunction. This solenoid controls vacuum to the EGR valve. When it fails, EGR valve operation is impaired.

What are the symptoms of P1409 on a Lincoln MKX?

Common symptoms of P1409 include: Check Engine Light, EGR valve stuck open or closed, Rough idle (if stuck open), Knocking/pinging (if stuck closed), Failed emissions.

What causes P1409 on a 2018-2018 Lincoln MKX?

Common causes of P1409 include: Faulty EVR solenoid, Wiring issue to EVR solenoid, Clogged vacuum lines to EGR valve, PCM driver failure.

Last updated: March 2026

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