Parts for your 2004 Honda Odyssey-Camshaft sensor

2004 Honda Odyssey Camshaft Position Sensor

Based on the Honda Factory Service Manual for the 1999–2004 Odyssey, Honda’s OBD‑II diagnostic documentation for DTCs P0340/P0341, and the OEM Honda parts catalogue for the 3.5‑litre J‑series V6, the 2004 Honda Odyssey is fitted with a camshaft position sensor (CMP). It’s mounted on the rear cylinder head (bank 1) near the timing belt end and is integral to fuel injection timing and misfire detection.

The CMP sensor tells the engine control unit exactly where the camshaft is in its rotation. Paired with the crank sensor, it lets the ECU fire the injectors and coils at the right moment, improving cold starts, smoothness and efficiency. When it goes out of whack, the Odyssey can run rough, stall at idle, and light the check‑engine lamp.

Owners and workshops looking after a 2004 Odyssey should treat the CMP sensor as a “fit‑and‑forget” item that only needs attention if symptoms show, but it’s still smart to give it a quick visual during scheduled services. A light oil weep onto the connector or a brittle plug boot can cause intermittent faults that mimic a dying sensor.

• Common signs of trouble: hard starting, hesitation, poor economy, random stalling, and codes P0340 or P0341.
• Quick checks: inspect the wiring loom behind the engine under the cowl, look for oil contamination at the sensor O‑ring, and make sure the connector pins are clean and snug.

Replacement is straightforward with basic tools. Under the bonnet, unplug the connector, remove the retaining bolt, and ease the sensor out. A smear of clean engine oil on the new O‑ring helps it seat without pinching. Refit the bolt, reconnect the plug, clear any stored codes, and take it for a gentle test drive to confirm smooth running. If the code returns, verify harness integrity and ECU grounds before condemning the new part.

There’s no periodic maintenance interval for the CMP sensor itself, but it benefits from tidy housekeeping: fix rocker cover leaks promptly, route the loom away from heat where possible, and keep connectors dry. Using quality OEM‑equivalent parts pays off here—cheap sensors can introduce timing jitter that the ECU struggles to filter, especially noticeable at idle with the air‑con on during Kiwi and Aussie summers.

Popular questions

Where is the camshaft sensor on a 2004 Honda Odyssey?
It sits on the rear (firewall‑side) cylinder head, near the timing belt end. Access is from above under the cowl, a small mirror or torch helps. Look for a single small sensor held by one bolt with a two‑ or three‑pin connector.

Can a bad camshaft sensor cause stalling or hard starts?
Yes. If the CMP signal is missing or erratic, the ECU can lose sync, leading to long crank times, rough idle, or random stalling. It often throws codes P0340 or P0341, but intermittent wiring faults can cause stall/hesitation without immediately logging a code.

Do I need to program the ECU after replacing the sensor?
No programming is required. Fit the new sensor, clear any stored DTCs, and the ECU will relearn on the next drive cycle. If issues persist, check wiring, grounds, and oil contamination at the connector.