Parts for your 2010 Toyota Mark x-Knock sensor

2010 Toyota Mark X knock sensor — purpose, servicing and FAQs

Technical sources confirm the 2010 Toyota Mark X (GRX130 series, 4GR‑FSE 2.5 V6 and 2GR‑FSE 3.5 V6) is fitted with knock sensors. The Toyota Mark X GRX130 Repair Manual (Engine/Control System — SFI System) lists the knock sensor and related DTCs (P0325, P0327, P0330, P0333), the Toyota Electronic Parts Catalogue (EPC) shows two knock sensors for both engines, and Toyota wiring diagrams depict dedicated knock sensor circuits to the ECM for each bank. This isn’t a model that runs without knock sensing, it relies on it.

The knock sensor on a 2010 Toyota Mark X is there to keep the alloy V6 happy under the bonnet. It “listens” for detonation (knock) and lets the engine computer trim ignition timing on the fly, so the car can run smoothly on local petrol and still make decent power. With the GR-series engines, there are two sensors tucked in the V of the block, one for each bank, which gives the ECM a clear ear on both sides of the engine. That means better protection, better fuel economy, and less chance of nasty piston or bearing damage if fuel quality drops or the engine is worked hard.

It’s not a routine service item in the way oil and filters are, but it matters. If a knock sensor goes out of spec or the wiring plays up, the Mark X will usually light the MIL and log a code like P0325/P0327 (Bank 1) or P0330/P0333 (Bank 2). Drivers might notice dull performance, higher fuel use, or even a bit of pinging under load. Because the sensors live under the intake manifold, access isn’t exactly a two-minute spanner job, most owners leave replacement to a workshop.

• Diagnosis first: confirm with scan tool data and DTCs, then check the harness and connector condition before condemning the sensor.
• Replacement tips: the intake manifold needs to come off, use new manifold gaskets, keep the valley clean, and route the harness exactly as per the manual to avoid chafe.
• Use quality parts: genuine or high‑grade OEM‑equivalent sensors keep the calibration spot‑on.
• Torque matters: install to the factory spec on a clean, dry block surface, don’t use sealant on the sensor seat.
• After the job: clear codes, perform a road test with a few steady pulls so the ECU can relearn knock control.
• Prevention: stick with the recommended octane (95 RON or higher is a safe bet in AU/NZ), keep cooling and PCV systems healthy, and avoid blasting the engine bay with water around connectors.

Look at a knock sensor replacement when faults show up, rather than on a fixed kilometre interval. Done right, it’s a fit‑and‑forget repair that keeps the Mark X lively and protected.

Does the 2010 Toyota Mark X have one or two knock sensors?

It has two—one per cylinder bank on the V6. That layout gives the ECU accurate feedback from each side of the engine, so timing adjustments are precise and knock control stays tight.

What are the symptoms of a failing knock sensor on a Mark X?

Common signs include a Check Engine light with codes like P0325/P0327 or P0330/P0333, sluggish performance, higher fuel consumption, and sometimes audible pinging under load. The ECU may pull timing to protect the engine, which makes the car feel a bit flat.

Can it be driven with a faulty knock sensor?

It will usually run in a safe, low‑timing mode, but that’s a short‑term band‑aid. Prolonged driving risks poor economy and, in the worst case, knock that isn’t managed properly. Best to book it in and sort the fault as soon as practical.