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2003 Nissan Altima 2.5 Engine Code P0340: Camshaft Position Sensor Malfunction Diagnosis and Fix

Model: 2003 Nissan Altima 2.5 Fault Code: P0340 Posted: 2008-07-10 22:36

Hi everyone, I'm new to this forum and seeking help with a recurring issue on my 2003 Nissan Altima 2.5. The car died while idling in traffic, and after restarting, the 'Service Engine Soon' light came on. My OBD-II scanner detected code P0340 — Camshaft Position Sensor Circuit Malfunction. The vehicle started fine initially but began exhibiting hesitation during restarts—particularly when I stopped for gas and tried to re-start it. It now takes several attempts to crank over, which is concerning. I understand that this fault can stem from the sensor itself, wiring issues, or a problem with the Powertrain Control Module (PCM). What exactly is the PCM? Where should I begin troubleshooting? I'm planning to inspect the wiring first. Any guidance on where the camshaft position sensor is located and how to properly replace it would be greatly appreciated. Thanks for any insights! -- User

Related fault codes
P0340
Comments (8)
Anonymous 2008-07-11 05:10

If the timing belt hasn't slipped, the camshaft position sensor is likely faulty. Some 2003 Nissan Altima models had known issues with this component and were subject to a recall—check your vehicle’s history for any recall notices. I'd recommend replacing the sensor first before suspecting PCM or wiring problems.

Anonymous 2008-07-11 18:30

Thanks for your message. What does 'PCM' stand for? I'm not familiar with that term.

Anonymous 2008-07-12 07:52

PCM stands for Powertrain Control Module — the main computer in the vehicle that manages engine and transmission functions.

Anonymous 2008-07-14 11:45

Thanks for your reply. If you have a reliable source with diagrams showing where the camshaft position sensor is located and step-by-step instructions for replacement, I'd appreciate it. That would be very helpful. Best regards, -Kmelsr

Anonymous 2008-07-22 22:41

I recently purchased a new camshaft position sensor for $30 with tax from All Parts (it's the original Nissan part). Kragen listed it at $48 without tax, so I saved money. I found a helpful guide on how to remove and replace the sensor here: http://www.paulstravelpictures.com/Niss ... t-070.html. The sensor is slightly different from others—be sure to match the part correctly. I'll update if the issue returns after clearing the code. Cheers, -Kmelsr

Anonymous 2008-07-23 04:58

I believe Nissan issued a recall for certain models involving camshaft or crankshaft position sensors—worth checking your vehicle’s service history.

Anonymous 2008-08-11 15:14

The issue was indeed the camshaft position sensor. After replacement, the car runs smoothly and no further issues have occurred. Thanks for the help! Cheers, -Kmelsr

Anonymous 2008-08-11 23:41

Thanks for sharing your update—it's very helpful to others facing similar problems.