P0407 means the EGR position sensor 'B' is sending a voltage below the normal operating range. Sensor B exists on engines with dual EGR valves (V6 and V8 diesels) or on petrol engines that use a primary and secondary feedback sensor. The fault is almost always wiring or a failed sensor shorted to ground.
DTC/P0407·Audi
P0407 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)Audi
P0407 on a Audi means the EGR position sensor 'B' is sending a voltage below the normal operating range. Sensor B exists on engines with dual EGR valves (V6 and V8 diesels) or on petrol engines that use a primary and secondary feedback sensor. The fault is almost always wiring or a failed sensor shorted to ground.
Repair cost on Audi€88 - €913
What does P0407 mean on a Audi?
Audi A4
2010–2024P0407 is most common on the A4 3.0 TDI V6 (CCWA, CTBA, CAPA codes), which uses two EGR valves with two position sensors. Sensor B is the bank-2 EGR position. The harness for bank 2 routes behind the engine and is hard to access. Many shops replace both EGR valves together on high-mileage 3.0 TDI cars to avoid a repeat job. VCDS or ODIS adaptation reset for both banks is mandatory.
What causes P0407 on a Audi?
Beyond the generic causes listed on the main P0407 page, these are the Audi-specific patterns we see most often:
Audi A43.0 TDI V6 bank-2 EGR position sensor failure (sensor B)
Audi A4Both EGR valves usually replaced together on high-mileage cars
How to diagnose P0407 on a Audi with OBD2
Follow these steps to pinpoint the root cause of P0407:
- Identify which physical sensor is sensor B (workshop manual). On V6/V8 diesels, this is usually the bank opposite to sensor A
- Back-probe the sensor B signal wire. A healthy sensor at rest reads 0.5–1.0V. Below 0.2V indicates short to ground
- Verify 5V reference and ground at sensor B connector. If 5V reference is missing, check whether sensor A is also affected
- Inspect the harness branch for sensor B for chafing against the EGR cooler or exhaust manifold heat shield
- Replace sensor B (or the integrated valve assembly) if wiring tests good and signal reads steadily low
How much does P0407 cost to fix on a Audi? (EUR)
Estimated repair costs on a Audi (Audi parts and labour typically run 25% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0407 on Audi
These codes commonly cluster with P0407 on Audi vehicles:
FAQ: P0407 on Audi
What is the difference between EGR sensor A and sensor B?
Sensor A is the primary EGR position feedback. Sensor B is the secondary, present on engines with two EGR valves (most V6/V8 diesels) or on engines that use a redundant feedback sensor. On most 4-cylinder engines there is no sensor B, so P0407 only appears on more complex setups (Audi 3.0 TDI V6, Mercedes V6 diesels, some BMW B57).
Can I drive with P0407?
Short-term yes. The ECU disables the affected EGR bank and falls back on the other bank, causing uneven idle and reduced power. Diesels may enter limp mode. Plan the repair within a couple of weeks to avoid carbon buildup or DPF problems.
Does my 4-cylinder car have an EGR sensor B?
Usually no. P0407 on a 4-cylinder engine usually means the workshop manual labels the existing single sensor as 'B' due to manufacturer convention, or the engine has a primary plus secondary feedback (rare). On VW EA189/EA288, BMW N47/B47, and Mercedes OM651, the relevant code is normally P0405 not P0407.
Is repairing P0407 worth it on a high-mileage diesel?
Yes, in most cases. EGR sensor or valve replacement is far cheaper than dealing with a clogged DPF, NOx sensor faults, or AdBlue limp-mode countdown that result from continued EGR failure. On Audi 3.0 TDI V6 with dual EGR, budget for both sides to be inspected, since one failure often signals the other is close behind.
Looking for the full P0407 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0407 guideSkanyx · Audi
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