Parts for your 2017 Toyota Mark x-Camshaft sensor

2017 Toyota Mark X Camshaft Sensor

Toyota’s own technical references confirm the 2017 Toyota Mark X (GRX130 series) absolutely uses camshaft position sensors. The Toyota Mark X GRX130 Repair Manual (Engine Control – SFI and VVT-i System), the Electrical Wiring Diagram for the 2016–2019 Mark X, and Toyota’s Electronic Parts Catalogue list dedicated camshaft position sensors for both banks on the 4GR‑FSE 2.5L and 2GR‑FSE 3.5L V6 engines. These are typically identified as right-hand and left-hand intake cam sensors and are essential for sequential fuel injection and Dual VVT‑i control.

On this V6, the camshaft sensor’s job is to tell the engine control module exactly where each intake cam is in its rotation, so timing for spark, fuel, and VVT‑i advance/retard stays on the money. That means better cold starts, smooth idle, crisp throttle response, strong fuel economy, and cleaner emissions. If a sensor drops out or reads poorly, the ECM can’t sync cam-to-crank angle properly, which can trigger a check engine light, sluggish performance, rough running, longer cranking, higher fuel use, or limp-home behaviour. Common diagnostic trouble codes include P0340/P0341 (Bank 1) and P0345/P0346 (Bank 2).

There’s no scheduled replacement interval for the camshaft sensors on a 2017 Mark X, but they do benefit from basic checks during routine servicing:

• Inspect connectors and wiring looms at the front of both cylinder heads for chafe, oil intrusion, and brittle insulation.
• Keep the area clean—avoid blasting with high-pressure water, use electrical contact cleaner if needed.
• If chasing cam/crank correlation or VVT‑i faults, verify oil quality and level first, dirty or incorrect oil can mimic sensor issues.

If a sensor needs replacing, it’s a straightforward job for a competent home mechanic:

1. Park safely, let the engine cool, and disconnect the negative battery terminal.
2. Remove the engine cover, unplug the sensor connector on the affected bank, and undo the small retaining bolt.
3. Gently twist and pull the sensor out. Lightly oil the new O‑ring on the replacement sensor, seat it squarely, and refit the bolt (tighten to the spec in the Toyota manual—these are light fasteners).
4. Reconnect the plug, refit the cover, reconnect the battery, clear codes, and perform an idle relearn if required.

Use quality OEM or equivalent parts, and don’t swap sensors bank-to-bank unless directed by a test plan. When in doubt, a scan tool check of cam vs crank signals—and, ideally, an oscilloscope trace—will help confirm a proper fix.

FAQs

Does the 2017 Mark X have one or two camshaft sensors?
It has two—one on each cylinder bank monitoring the intake camshafts. The ECM compares both cam signals to the crank signal for precise sequential injection and Dual VVT‑i control.

What fault codes point to a failing camshaft sensor on a Mark X?
Typical codes include P0340/P0341 for Bank 1 and P0345/P0346 for Bank 2. You may also see related VVT‑i performance or correlation codes if oil quality is poor or timing components are out of spec.

Do camshaft sensors need routine replacement?
No set interval. They’re replaced on condition—when diagnostics confirm a fault. Regular checks of wiring, connectors, and engine oil quality during servicing help prevent false alarms and extend sensor life.