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Home/DTC Codes/Lincoln/MKX/2018-2018 3.7L V6/P0403
P0403

EGR Control Circuit

2018-2018 Lincoln MKX 3.7L V6

Moderate SeverityPowertrainGeneric (SAE)

The 2018 Lincoln MKX is equipped with a 3.7L V6 engine. Below you'll find detailed p0403 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.

Description

Malfunction in the EGR valve control circuit (electrical EGR valves).

Symptoms

  • Check Engine Light
  • EGR not functioning
  • Increased emissions

Common Causes

  • Faulty EGR valve
  • Wiring damage
  • PCM driver failure
  • Corroded connector

Diagnostic Steps

  1. Test EGR valve solenoid resistance
  2. Check wiring
  3. Command EGR with scan tool
  4. Test PCM output

Repair Notes

Replace EGR valve or repair wiring.

Related Codes

P0400Exhaust Gas Recirculation (EGR) FlowP0404EGR Control Circuit Range/Performance

Other Powertrain Codes

P0403 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 P0403 mean on a 2018-2018 Lincoln MKX?

P0403 stands for "EGR Control Circuit". Malfunction in the EGR valve control circuit (electrical EGR valves).

What are the symptoms of P0403 on a Lincoln MKX?

Common symptoms of P0403 include: Check Engine Light, EGR not functioning, Increased emissions.

What causes P0403 on a 2018-2018 Lincoln MKX?

Common causes of P0403 include: Faulty EGR valve, Wiring damage, PCM driver failure, Corroded connector.

Last updated: March 2026

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