What are the symptoms of P0406?

Check Engine Light with EGR position sensor signal too high; EGR position sensor excessive signal strength issues; Position monitoring signal limiting problems; EGR system operation with high position signal; Emission control monitoring system signal overload conditions; Failed sensor tests due to high signal amplitude

Faulty EGR position sensor (G98) with excessive output; Short circuit in sensor signal wiring; Electrical interference affecting sensor circuit; Sensor mounting or calibration issues causing high output; Signal conditioning problems in sensor circuit; Engine control module sensor input protection issues

Replace faulty EGR position sensor (G98); Repair short circuits in sensor wiring; Shield sensor circuit from interference; Adjust sensor mounting and calibration; Fix sensor circuit signal conditioning; Reset EGR position monitoring system

Do OBD-II codes differ between vehicle manufacturers?

Yes, while P-codes (powertrain) follow SAE J2012 standards, manufacturers may implement additional parameters or variations. U-codes (network communication) are particularly manufacturer-specific and can have different meanings for different brands.

Should I always check my vehicle's service manual?

Absolutely. Your vehicle's official service manual provides manufacturer-specific interpretations, diagnostic procedures, and repair instructions tailored to your exact model. Generic OBD-II code databases provide general guidance, but factory documentation ensures accurate diagnosis.

Complete diagnostic information for error code P0406

⚠️

Manufacturer-Specific Variations

This code (P0406) may have different meanings or additional parameters depending on your vehicle's make, model, and year. Always verify with your vehicle's service manual or a qualified technician before attempting repairs.

P0406

Powertrain Code

Exhaust Gas Recirculation (EGR) (G98), Signal too High

Emission ControlMODERATE👁 Views: 20

Description

EGR position sensor A (G98) signal too high

Common Symptoms

Check Engine Light with EGR position sensor signal too high
EGR position sensor excessive signal strength issues
Position monitoring signal limiting problems
EGR system operation with high position signal
Emission control monitoring system signal overload conditions
Failed sensor tests due to high signal amplitude

Possible Causes

Faulty EGR position sensor (G98) with excessive output
Short circuit in sensor signal wiring
Electrical interference affecting sensor circuit
Sensor mounting or calibration issues causing high output
Signal conditioning problems in sensor circuit
Engine control module sensor input protection issues

Diagnosis Steps

Test EGR position sensor (G98) signal amplitude
Check for short circuits in sensor wiring
Monitor for interference in sensor circuit
Verify sensor mounting and calibration
Test sensor circuit signal conditioning
Check engine control module sensor input protection

Repair Solutions

Replace faulty EGR position sensor (G98)
Repair short circuits in sensor wiring
Shield sensor circuit from interference
Adjust sensor mounting and calibration
Fix sensor circuit signal conditioning
Reset EGR position monitoring system

Prevention Tips

Regular sensor signal amplitude monitoring
Protect sensor wiring from shorts
Maintain proper sensor calibration

⚡

Working with ECU firmware? Remove DTCs directly from firmware files

Our free Firmware DTC Remover detects and removes hardcoded fault codes directly from ECU firmware files — no software needed. Supports BMW/MINI (EDC16, EDC17, MEVD17) and VAG Group (EDC17). Free: 3 removals/day.

Try DTC Remover — Free →

← Back to OBD Codes List Home