2003 Chevrolet Trailblazer P0105 and P0107 Codes: CEL On, Reduced Engine Power, Map Sensor Voltage Issues

I replaced the leaking fuel pump in my 2003 Chevrolet Trailblazer, and the vehicle ran smoothly for several weeks. However, after passing inspection, it started throwing a P0107 code with reduced engine performance. The MAP (Manifold Absolute Pressure) sensor connector shows only 1 to 2.5 volts when referenced to a 5-volt signal wire—significantly below normal. The P0107 code does not clear when the ignition is on and the engine is off, though it briefly clears during driving with throttle movement. After a few minutes of operation, the vehicle rethrows both P0105 and P0107 codes, resulting in reduced engine power. I'm seeking help identifying the correct MAP sensor wiring diagram, any components that share this circuit, or where to test the ECM for proper 5-volt reference. Additionally, the vehicle occasionally throws brake/ABS warnings—though infrequently—I'm unsure if these are related to the MAP sensor fault.