The Quick Answer above is the generic definition. What follows is the model-specific detail for the BMW models that log P0403.
DTC/P0403·BMW
P0403 on BMW: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)BMW
P0403 on a BMW means the ECU has detected a fault in the circuit that controls the EGR valve: it expected a specific voltage or current response and did not see it. The valve's own solenoid or motor is part of that circuit, so the cause is usually the valve itself, its connector or its wiring, and on electric valves, carbon that jams the valve can load the motor enough to trip the circuit monitor.
Typical repair cost, all makes€68 - €670
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BMW 3 Series
2007-2024The N47 and B47 diesel EGR valve solenoid is a frequent failure point on the 320d and 318d. The connector sits very close to the turbo heat shield, and thermal cycling eventually cracks the pin seals, letting moisture into the contacts, so P0403 on these engines often turns out to need both a new valve and a connector repair.
What causes P0403 on a BMW?
Beyond the generic causes listed on the main P0403 page, these are the patterns noted for BMW models:
BMW 3 SeriesN47/B47 EGR solenoid coil failure from constant thermal cycling
BMW 3 SeriesConnector pin corrosion from turbo heat shield proximity
How to diagnose P0403 on a BMW with OBD2
Follow these steps to pinpoint the root cause of P0403:
- Inspect the EGR valve connector for corrosion, bent pins, and water intrusion
- Unplug the connector and measure resistance across the solenoid terminals. Compare against the workshop manual spec (typically 5-15 ohms for solenoids, 2-10 ohms for motors)
- Back-probe the connector and verify the ECU is supplying voltage and ground in the correct sequence when the EGR is commanded
- Inspect the harness between the ECU and EGR valve for chafing, especially where it routes near hot exhaust components
- If the solenoid and wiring test good, remove the valve and check whether carbon is mechanically binding the pintle
How much does P0403 cost to fix on a BMW? (EUR)
Estimated repair costs for P0403 in EUR, compiled across makes. Expect BMW parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Codes related to P0403
These codes are often seen alongside P0403 or point to related issues, on any make:
Looking for the full P0403 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0403 guideSkanyx · BMW
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