Fault Family System: Powertrain (P-Codes) 20 SAE Codes

EGR Control Circuit

Diagnostic & Technical Explanation

Code P0403 (EGR A Control Circuit/Open) sets when the ECM detects an open circuit, out-of-range voltage, a learning-limit exceeded condition, or a mechanically stuck-open/stuck-closed report while driving an EGR control valve, an EGR throttle valve used to assist EGR flow, or the associated control processor. Causes are a failed EGR valve/throttle solenoid or motor, a corroded connector, carbon buildup mechanically jamming the valve, or damaged control wiring back to the ECM.

These 20 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 20 times.

Codes in this family (20)

Code	Definition	Repair coverage
P0403	EGR A Control Circuit/Open	4 ranked fixes
P0404	EGR A Control Circuit Range/Performance	4 ranked fixes
P042E	EGR A Control Stuck Open	4 ranked fixes
P042F	EGR A Control Stuck Closed	4 ranked fixes
P045A	EGR B Control Circuit	4 ranked fixes
P045B	EGR B Control Circuit Range/Performance	4 ranked fixes
P045C	EGR B Control Circuit Low	4 ranked fixes
P045D	EGR B Control Circuit High	4 ranked fixes
P045E	EGR B Control Stuck Open	4 ranked fixes
P045F	EGR B Control Stuck Closed	4 ranked fixes
P0487	EGR Throttle Control Circuit A /Open	4 ranked fixes
P0488	EGR Throttle Control Circuit A Range/Performance	4 ranked fixes
P0489	EGR A Control Circuit Low	4 ranked fixes
P0490	EGR A Control Circuit High	4 ranked fixes
P049D	EGR A Control Position Exceeded Learning Limit	4 ranked fixes
P049E	EGR B Control Position Exceeded Learning Limit	4 ranked fixes
P04FA	EGR A Control Temperature Too High	4 ranked fixes
P04FD	EGR Actuator A Control Processor Performance	4 ranked fixes
P2141	EGR Throttle Control Circuit A Low	4 ranked fixes
P2142	EGR Throttle Control Circuit A High	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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