Engine jerking at highway speed — EGR failure

Tags: #egr · #obd · #warranty

Symptom: the engine jerks or hesitates when coasting at highway speed (~100 km/h) and easing off the throttle in a high gear (4th or 5th)¹². Diagnosis: an OBD scanner must be used to read the fault code, which points to EGR (exhaust gas recirculation) valve failure — not every shop's scanner can read this system's errors, so a capable scanner is essential³⁴. Fix: replace the EGR valve; one owner had this done as a warranty replacement at the dealer⁵⁶. Note: other symptoms that look similar may have different root causes, so always run a diagnostic scan before assuming EGR and replacing the part.

Code P0405 (EGR position sensor "A", low signal). An owner asked whether others had met OBD code P0405, which means the position sensor "A" of the EGR valve reads a low signal⁷. One reply advised cleaning the sensor first and, if it is clean, checking all tubes and hoses for cracks, splits or vacuum leaks, then going to a diagnostician⁸⁹. The owner (IBRAIM) objected that many people say the sensor is already clean and the fault lies elsewhere, and that replacing the sensor is expensive (no figure given)¹⁰.

Media

Photo showing OBD scanner readout with EGR-related error code

Photo showing OBD scanner readout with EGR-related error code

Related pages

• Transmission oil cooler failure — coolant/ATF mix
• Power steering pump failure — warranty denials
• Engine jerking on light throttle in traffic
• Engine shuddering at 2.5k RPM and cruise
• Engine mount failure — symptoms and inspection

Sources

This page is compiled from 10 community messages. Every fact carries a numbered reference to its original author and message.

Last updated: 2026-10-29