P0408 - Exhaust Gas Recirculation Sensor B Circuit High

The EGR sensor B signal is higher than expected.

Code Overview

The EGR sensor B signal is higher than expected.

Common Causes

• Failed EGR sensor
• Short to voltage
• Damaged wiring or connector

Diagnostic Steps

1. Inspect the EGR sensor connector and wiring
2. Check signal voltage against expected range
3. Inspect for carbon buildup or sticking components

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

Browse the closest code-family pages when the same fault pattern often shows up nearby.

Next Steps

Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.