It seems that none of the printer's sensor is faulty, in fact, the printer has a faulty firmware on the formatter.
Your printer may need replacement of the formatter board, however, please try the following before swapping the formatter.
HP LaserJet P2015 Printer Series - Paper Jam Light Solid
The HP LaserJet P2015 may come up with Paper Jam Light solid and would show the same light pattern even if the printer is power cycled.
The Light pattern is as shown in the diagram below.
Perform the following tasks in the order listed.
1. Reset the printer using the Super NVRAM initialization. The procedure is
a. Turn off the printer
b. Press and hold the GO button
c. Turn on the printer and continue to hold the Go button for at least 50 seconds. During this process the Attention, Ready and Go light turns on. Then the Attention and Ready light turns off, leaving just the Go light illuminated.
d. Release the Go button. The Go, Attention and Ready lights turn on.
e. Press and hold the Go button. All lights turn off. During the next three seconds, the Go, Ready and Attention lights turn on in that order, one per second.
f. Release the Go button to perform the initialization. The control panel lights begin cycling from front to back. After the Super NVRAM initialization process is complete, the printer returns to the ready state.
2.Unplug the power cord when the printer is on and leave it unplugged for 10 Seconds.
3. Turn the printer back on.
If the above steps resolve the issue, then print a configuration page and check the firmware version and the formatter board no.,
If the firmware version is below: 20080312, then your printer needs to upgrade the firmware, however the firmware can be upgraded only onl those models whole formatter board's third number from left is 0, 1 or 2, eg: JK0xxxx
If the 3rd number from left of the formatter board no is anything other than 0, 1, 2, then firmware cannot be flashed.
Please let me know the next update.