p0641 trouble code what is it, and how do I fix it

Question

I was driving and my car and all of a sudden it said engine power reduced and it stalls and has trouble accelerating. I read that it was problems with the ECM.?.? Then it was having trouble running at all. it had another a/c code too but im not to concerned about that one. ANY HELP?

Answer 1

P0641 5 volt Referrence 1 circuit

It the vehicle had reduce power you should also have that code presenst also. And also the a/c code. this will narrow the trouble down. What the 5 volt refference 1 circuit does is provide 5 volt refference voltage for more than one sensor. Here are the 5 volts it supplies MAP (manifold absolute pressure ) sensor ,Fuel tank pressure sensor (FTP) Accelerator pedal position (APP), Air injection reactor (AIR) , Engine oil pressure (EOP) A/C refigerant pressure sensor (A/C), camshaft psotion sensor (CAM) and the crank position sensor (CKP) This 5 volt refference circuit is now considered a BUS . If one of these sensor short to ground, or shorts to voltage the rest of the sensor are affected. If the A/C code is present that short can be the cause of P0641 which has cause Reduce Power, You may just need the a/c pressure switch