P0405 on Ford
Exhaust Gas Recirculation Sensor 'A' Circuit Low
P0405 on Ford vehicles indicates exhaust gas recirculation sensor 'a' circuit low. Au7o has documented this code across 1 Ford model — most commonly on F-150. P0405 is a generic OBD-II code meaning the engine computer detected an abnormally low voltage signal from the Exhaust Gas Recirculation (EGR) sensor 'A' circuit. This sensor reports the EGR valve's position or flow, which the computer uses to control exhaust gas recirculation for lowering emissions and combustion temperatures. A low signal indicates the reading is below the expected range, often due to a wiring or sensor fault. It mainly affects emissions and may cause light drivability issues but is not an immediate safety concern. Typical repair costs on Ford range from $50 to $250, depending on the specific model and root cause.
Common Causes of P0405
- •Faulty EGR position sensor (or DPFE sensor)
- •Open, shorted, or corroded EGR sensor wiring/connector
- •EGR valve stuck or carbon-clogged
- •Loss of reference voltage or ground to the sensor
- •Poor connector contact / pin corrosion
- •Damaged EGR valve assembly
- •PCM fault (rare)
P0405 on Ford by Model
Ford F-150(1 issue)
- DPFE / EGR Pressure Sensor Failure — Rough Idle, Stalling, and P0401 (2-Valve Triton)1997-2004
The Delta Pressure Feedback EGR (DPFE) sensor and the EGR throttle-body spacer passages are a chronic Check-Engine source on 1997-2004 4.2L/4.6L/5.4L trucks. The ceramic DPFE sensor drifts or cracks, and the narrow 90-degree EGR elbow passages carbon up until flow is blocked, setting P0401 (insufficient EGR flow). The result is a rough idle, stumble or stall when coming to a stop, hesitation, and reduced fuel economy. It is frequently misdiagnosed as the EGR valve itself.
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View P0405 across all makes →Frequently Asked Questions
What does P0405 mean on Ford?▼
P0405 stands for "Exhaust Gas Recirculation Sensor 'A' Circuit Low." P0405 is a generic OBD-II code meaning the engine computer detected an abnormally low voltage signal from the Exhaust Gas Recirculation (EGR) sensor 'A' circuit. This sensor reports the EGR valve's position or flow, which the computer uses to control exhaust gas recirculation for lowering emissions and combustion temperatures. A low signal indicates the reading is below the expected range, often due to a wiring or sensor fault. It mainly affects emissions and may cause light drivability issues but is not an immediate safety concern. On Ford specifically, this code is documented across 1 model.
What causes P0405 on Ford vehicles?▼
Common causes on Ford: Faulty EGR position sensor (or DPFE sensor), Open, shorted, or corroded EGR sensor wiring/connector, EGR valve stuck or carbon-clogged, Loss of reference voltage or ground to the sensor, Poor connector contact / pin corrosion. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0405 on a Ford?▼
Repair costs on Ford range from $50 to $250, depending on the specific model and root cause.
Which Ford models have P0405 documented?▼
Au7o has documented P0405 on 1 Ford model: F-150.