A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
- Open signal wire or open sensor ground
- Sensor connector or wiring: corrosion, an open circuit, a chafed wire
- The sensor itself
What you can do yourself
- Check the knock sensor connector and its tightening torque.
- The ECU retards ignition timing: pull drops, fuel consumption rises.
OOleg’s tip: check the connector
Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.
Unplug and inspect connectors with the ignition off.
Find the part on Kaspi ShopBefore buying, check the part number or match the part by VIN in the Kaspi “Garage”.
OA case from Oleg’s practice
- Nissan X-Trail 2002 Check Engine on: P0328 (knock sensor) and P0350 (coil circuit). The codes showed where to look — coils, plugs, wiring and the sensor — not what to replace right away. How it went ↗
The explanation comes from the error code reference in the AvtoElektrik PRO app.