P0340: No CAM signal at Pcm

The vehicle cranks,
The vehicle starts. But it does not raise above 2500 rpm. When you diagonize it will indicate P0340: NO CAMSHAFT SENSOR SIGNAL AT PCM. On the signal circuit of the cam sensor, there was 4.91volts present. I bypass the circuit from PCM connector C2-34 to camshaft sensor connector terminal-1, the 5volts still exist. I replace the PCM, the 5volts still exist. Then I go to another car of the same model and I measured the signal circuit with igntion on; engine not running, it reads 40Mv, then I start it and it reads 0.4volts at idling.
So I don't know where the circuit is bridging causing the camshaft sensor no signal. So need help on how to trace the particular circuit causing this problem?

This is not COMPRESSION ISSUE, if it is COMPRESSION ISSUE the vehicle will not be starting at all.

If the engine is okay this code will not make it not rev FYI;
I want to ask you:
how many volts or millivolts does the camshaft sensor return to the PCM on the signal circuit?
Do your test and reply me soon.

I have check the camshaft sensor wiring and it is not short at any point, the wiring was ok, Then I notice from the daydream that Map sensor was reading 0.00G/ms instead of 4.57G/me. Can you please send the diagram for manifold absolute pressure sensor for me to check it for short voltage or power?