If your Altima has trouble starting at times, you might have a problem with your camshaft position sensor. Some symptoms of having a faulty sensor include turning your car off when the engine is warm and having trouble restarting it, or having a jerky idle on your vehicle. The service engine error code on your vehicle will be read as P0340 on an OBD-II scanner. Fortunately, the sensor itself can be replaced without too much difficulty.
Remove the negative terminal of your battery to prevent electrical shock.
Locate the camshaft sensor. It looks like a black knob that is directly below the right side of the engine cover that reads "3.5 CVTC."
Remove the electrical connector that is attached to the sensor. You must first slide your finger under the sensor and push up on the unlock tab that locks the connector in place.
Remove the 10mm bolt that is securing the sensor with a 10mm socket.
Pull the sensor out of its socket. The O-rings may make it a bit difficult to remove, so pull firmly.
Take some of the oil that is in the sensor slot and put it on the O-ring of the new sensor.
Slide the new sensor into the slot and secure it with the 10mm bolt.
Reattach the electrical connector by snapping it back into place.
Reattach the negative terminal of your battery.
Ensure that your vehicle is functioning properly.
