Parts for your 2007 Toyota Mark x-Crank angle sensor

2007 Toyota Mark X crank angle sensor – what it does and when to replace it

Yes, the 2007 Toyota Mark X uses a crank angle sensor (commonly called the crankshaft position sensor). This is documented in Toyota’s Technical Information System (TIS) repair manual for the GRX120/GRX121 Mark X under the Engine Control (SFI/EFI) sections, which list the Crankshaft Position Sensor (NE) as a key input for ignition and injection control. The Toyota Electronic Parts Catalogue (EPC) for GRX120/121 also shows the crankshaft position sensor among engine electrical components for the 4GR‑FSE and 3GR‑FSE V6 engines. These GR‑series engines rely on both crank and cam signals to run VVT‑i and misfire monitoring.

On a 2007 Mark X, the crank angle sensor feeds the ECU with the exact position and speed of the crankshaft. That info fires the coils at the right moment, times the fuel injection, and lets VVT‑i do its thing smoothly. Without a clean signal, the engine can be hard to start, stumble, or cut out unexpectedly. It’s not a routine service item, but it’s one of those small parts that does a massive job in the background.

Typical clues the sensor is on the way out include long cranking or a no‑start when hot, random stalling at lights, a jerky tachometer, poor fuel economy, and stored fault codes like P0335/P0336. Because symptoms can mimic a cam sensor fault or a tired fuel pump, a proper scan with live data is the smart first step.

There’s no fixed replacement interval. Think of it as “inspect and replace if faulty.” During regular servicing, it’s worth checking the wiring loom around the back of the engine and the plug for oil contamination, heat damage, or loose terminals. If removing the sensor, look for metal fuzz on the tip and clean the mounting face so it seats squarely. Always fit a quality OEM‑equivalent unit and a fresh O‑ring if applicable.

On the Mark X V6, the crank sensor sits low at the rear of the engine near the transmission bellhousing. Access is usually from underneath. A basic replacement involves disconnecting the battery, unplugging the connector, removing the retaining bolt, withdrawing the sensor, lightly oiling the new O‑ring, installing the new sensor, and tightening to the workshop manual spec. After refit, clear codes and road‑test to confirm stable RPM and no stalling. If a crank sensor fault returns, inspect the trigger teeth (reluctor) and verify cam sensor signals, as the ECU needs both for clean sync.

• Common DTCs: P0335 (Crankshaft Position Sensor “A” Circuit), P0336 (Range/Performance)
• Best practice: diagnose first, replace with OEM‑quality, and protect the harness from heat
• Good time to check: when chasing hot‑start issues or intermittent stalls

FAQs

Where is the crank angle sensor on a 2007 Mark X?
It’s mounted low at the rear of the engine near the transmission bellhousing. On most cars it’s easiest to get to from underneath after safely raising the vehicle. Look for a small sensor with a single retaining bolt and a two‑ or three‑wire connector.

Can a bad crank angle sensor cause a no‑start?
Absolutely. If the ECU can’t “see” crank position, it won’t fire the injectors or coils. You might get long cranking, especially when hot, and codes like P0335. Once replaced and the codes cleared, starting and idle stability usually improve straight away.

Should the cam sensors be replaced at the same time?
Not automatically. If diagnostics point only to the crank sensor, replace that first. If there are related cam sensor codes or sync errors, test the cam sensors and wiring and consider replacing them as well, preferably with OEM‑quality parts.