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Parts for your 2004 Lexus Is-Camshaft sensor
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2004 Lexus IS camshaft sensor: purpose, service and replacement
Technical sources confirm the 2004 Lexus IS does use a camshaft position sensor. The Toyota/Lexus Electrical Wiring Diagram for the first‑gen IS (XE10, 2001–2005) identifies component G2 “Camshaft Position Sensor” feeding the ECM, and both the Lexus IS300 (2JZ‑GE VVT‑i) and IS200 (1G‑FE VVT‑i) factory repair manuals specify a CMP input for sequential injection and variable valve timing control. So yes, it’s fitted and it matters.
On the 2004 IS, the camshaft sensor tells the engine computer exactly where the cam is in its rotation. That lets the ECM fire injectors in sequence, time ignition precisely, and command the VVT‑i to sharpen response and keep fuel economy tidy. When the signal goes missing or skewed, they’ll often see long cranking, rough idle, flat spots, limp‑home behaviour and a glowing check‑engine lamp. Common fault codes include P0340 and P0341.
It’s not a scheduled replacement item in normal servicing. Instead, think of light maintenance: keep the top of the engine clean, fix any rocker cover leaks promptly so oil doesn’t wick into the connector, and inspect the wiring for brittle insulation. If the scanner shows cam/crank sync issues, or scope traces are messy, it’s time for testing and likely a new sensor.
Replacement is a straightforward driveway job for most owners, whether it’s the 1G‑FE IS200 or the 2JZ‑GE IS300.
- Disconnect the negative battery terminal.
- Pop off the engine cover. The sensor sits at the front of the cylinder head by the timing cover (single retaining bolt, sealed by an O‑ring).
- Unplug the connector and check for oil intrusion or green crust on the pins.
- Remove the 10 mm bolt, twist the sensor gently, and pull it out. Catch the old O‑ring.
- Lightly oil the new O‑ring, seat the sensor, and torque the bolt to about 8–10 N·m.
- Reconnect, clear codes, and road‑test to verify cam/crank synchronisation.
Tips they’ll appreciate: stick with quality (OE‑equivalent Denso) rather than bargain no‑name parts, if the plug was oily, address the valve cover gasket, and if a new sensor doesn’t resolve P0340/P0341, check the crank sensor, timing belt alignment, and grounds. A healthy cam sensor keeps the IS starting smartly, idling smoothly, and pulling cleanly across the revs—just what this Lexus was built to do.
Popular questions about 2004 Lexus IS camshaft sensors
Where is the camshaft sensor located?
On both IS200 (1G‑FE) and IS300 (2JZ‑GE) it’s mounted at the front of the cylinder head near the timing cover, held by a single 10 mm bolt with a sealed O‑ring. Remove the engine cover and it’s an easy spot under the bonnet.
If access feels tight, a small 1/4‑inch drive ratchet and wobble extension make life easier. Always unplug the connector before undoing the bolt.
What symptoms point to a failing camshaft sensor?
Common signs include long cranking, intermittent stalling, rough idle, sluggish throttle, and the check‑engine light—often with P0340 or P0341 logged. Fuel economy can drop and the car may enter a reduced‑power mode.
Because these symptoms can overlap with crank sensor or timing belt issues, scan‑tool data and basic electrical checks are the best way to confirm the culprit.
Can it be cleaned or should it be replaced?
The sensor itself isn’t serviceable, if it’s electrically weak, replacement is the fix. That said, cleaning an oily connector and repairing damaged wiring can restore a good signal if the sensor tests fine.
If oil contamination is present, replace the sensor’s O‑ring and sort any valve cover leaks to prevent a repeat fault.
