No. P20E8 means “Reductant pump control circuit low.” P306D is specifically fluid QUALITY related. However, both are AdBlue system faults.
While the code suggests a major mechanical failure, the fix is often simpler than expected. Here is the breakdown of how we diagnosed and fixed a P306D error on a Peugeot 308.
When the P306D code registers in your Peugeot’s ECU, you will likely experience a combination of the following symptoms: p306d peugeot fixed
Owners often find that the error is intermittent. It might trigger at (around 800 rpm) or in heavy traffic, where the car expects one air pressure (e.g., 960 mbar) but detects another (e.g., 990–1000 mbar). Strangely, driving at high motorway speeds can sometimes make the error "disappear" for hundreds of miles because the throttle remains open and stable. The Fixing Journey
Remove the fuel pressure regulator from the high-pressure pump (usually held by two or three Torx bolts). While the code suggests a major mechanical failure,
While the purge valve is the primary suspect, a weak battery can cause strange, unrelated fault codes on modern Peugeots, including coherence errors.
For a definitive diagnosis, use a PSA-specific diagnostic tool like . Standard OBD-II scanners may only give the generic code, whereas Diagbox can provide the specific sub-codes (like P306D-22) and live data on throttle position versus air pressure, allowing you to see exactly where the mismatch occurs. It might trigger at (around 800 rpm) or
You won’t just see a code. The car will typically exhibit one or more of these symptoms:
If live data shows erratic jumps in pressure that do not match physical engine behavior (e.g., the scanner reads 2000 bar while the engine idles perfectly fine for a few seconds), the sensor is likely faulty.