Camshaft sensors, formally called camshaft position sensors, help your engine maintain emission and idle efficiency. The sensor itself cannot be fixed; it must be replaced. A faulty camshaft position sensor will always result in a "Check Engine" light. The Chrysler PT Cruiser has a fairly large engine for such a small engine bay. Because of this, you must remove the air intake assembly before accessing the camshaft position sensor.
Let your engine cool for at least 30 minutes. Open the bonnet, and loosen the nut from the negative (black) battery cable. Slip the cable away from the battery terminal.
Unfasten the air intake clamps, and loosen the screw on the hose clamp. Remove the top of the air intake assembly and remove the filter. Keep the filter covered and in a clean area.
Lift the bottom portion of the air intake box, and set it aside. The bottom portion is attached by clips; pull the box up to detach the clips and separate the box from its mount.
Push the red tab (on the camshaft sensor harness) toward the camshaft sensor. Press the connection tab, and pull the harness to unhook it from the camshaft sensor.
Remove the two camshaft sensor mounting bolts with the socket wrench. Lift the old sensor from the engine bay, and discard it.
Clean the mounting point with a dry shop towel. Insert the new gasket into the new camshaft sensor and mount it. Tighten the bolts to 13 Nm (115 inch-pounds). Reconnect the camshaft harness, and pull the red tab back in place.
Snap on the bottom portion of the air intake box. Install the filter and replace the cover. Reattach the air intake hose to the box and tighten the screw.
Most new camshaft position sensors include gaskets in their packaging. If your replacement sensor does not have a gasket, you must buy one. Do not install the sensor without a new gasket; it will become faulty almost immediately.
Observe all safety precautions to prevent burns and electrical shock.