P0403 - Exhaust Gas Recirculation Circuit Malfunction

EGR control circuit fault detected.

Treat the code as the starting point: compare symptoms, likely causes, and repair paths before pricing parts or moving into an estimate.

Code Overview

EGR control circuit fault detected.

Common Causes

• Wiring or connector fault in the EGR control circuit
• Failed EGR solenoid or actuator
• Poor power or ground supply to the EGR valve
• ECM driver fault in rare cases

Symptoms

• Check-engine light with possible rough idle
• EGR function may not respond when commanded
• Failed emissions test or part-throttle drivability complaints

Diagnostic Steps

1. Inspect the EGR wiring and connectors for damage or corrosion
2. Check power, ground, and control signals at the EGR valve or solenoid
3. Measure solenoid or actuator resistance if service information supports it
4. Confirm the circuit fault before replacing the valve or control module

Repair Difficulty

Moderate

General difficulty estimate for the most common repair path.

Likely Repairs & Cost Guides

Use symptoms, scan data, and quick checks to confirm the likely repair path before pricing parts. The estimator helps compare repair paths before replacing anything unnecessarily.

Related OBD Codes

Browse nearby code-family pages when the same fault pattern overlaps across systems, such as misfire, lean fuel trim, EVAP sealing, cooling, or charging faults.

Next Steps

Move from code lookup to diagnosis, then estimate the likely repair only after symptoms, causes, and checks point to the same path.