Parts for your 2009 Toyota Mark x-Crank angle sensor

2009 Toyota Mark X crank angle sensor (crankshaft position sensor)

The 2009 Toyota Mark X (GRX130/133) with the 4GR‑FSE 2.5L and 2GR‑FSE 3.5L V6 engines does use a crank angle sensor, more commonly called a crankshaft position (CKP) sensor. Toyota’s New Car Features (NCF) documentation for these GR-series engines identifies the NE crankshaft sensor working alongside the camshaft (G) sensors, and the Toyota Repair Manual lists DTCs P0335–P0339 specifically for the CKP circuit. The Toyota engine control EWD also shows the NE and G inputs feeding the ECM for ignition, injection and VVT‑i control.

On the Mark X, the crank angle sensor’s job is simple but critical: it reads a toothed wheel on the crank to tell the ECU exactly where the pistons are and how fast they’re spinning. That real-time signal lets the ECU fire the coils and injectors spot-on, and coordinate VVT‑i. If the signal goes missing or messy, the car can be hard to start, stumble, or stall, and the MIL will usually throw codes like P0335.

As part of regular servicing, the sensor itself isn’t a scheduled replacement item, but it’s smart to give it a once-over. Check the connector for oil ingress or corrosion, make sure the harness isn’t chafed near the front timing cover/block, and look for leaks that could contaminate the sensor. A failing sensor often shows up as intermittent no-start when hot, random misfires, or a sudden cut while cruising.

Replacement is straightforward with basic tools: disconnect the battery, access the sensor on the engine block/timing cover (varies slightly between 4GR‑FSE and 2GR‑FSE), unplug, remove the retaining bolt, and swap in a quality OEM-equivalent unit with a fresh O‑ring. There’s no manual adjustment, it’s a fixed mounting. After refit, clear any codes and let the engine idle so the ECU can settle trims. If diagnosing first, a scan tool that can read live RPM and sync status is gold, resistance checks on a magnetic pickup type can also help, but waveform testing is better.

Owners will save headaches by using genuine or well-regarded aftermarket sensors, keeping oil leaks in check, and ensuring the engine earths are sound. Done right, a new CKP sensor brings back crisp starts, smooth idle, and reliable timing control for heaps of kilometres under the bonnet.

• Common signs: hard starting, sudden stall, rough idle, MIL (P0335–P0339).
• Good practice: inspect connector/harness each service, fix oil leaks promptly.
• After replacement: clear codes and verify stable RPM signal on a scan tool.

FAQ

Where is the crank angle sensor on a 2009 Mark X?
The CKP sensor is mounted on the engine near the crankshaft reluctor, typically at the timing chain cover or lower block area. Access can vary slightly between the 4GR‑FSE and 2GR‑FSE, but it’s generally reachable from the front or underneath once shields are moved.

What symptoms point to a failing crank angle sensor?
Hot no‑start, random stalling, uneven idle, poor acceleration, and the check engine light with codes like P0335 are classic. If live data shows zero RPM while cranking, the CKP signal may be missing.

Do I need any programming after replacing the sensor?
No special programming is required. Fit the sensor, clear fault codes, and allow the engine to idle so trims stabilise. It’s wise to verify there are no stored or pending CKP/CMP correlation faults afterward.