98 Grand Prix GT-SES Code and some

[fst100]

im posting this for a friend of mine. here's what he typed in another forum,

"I was going down route 283 today around 68 and my tach went down to zero and my low track light came on. The car ran fine but it was just strange? Could anyone help me out please?"
later on his car through a few SES codes. Bank 1 knock sensor, Bank2 knock sensor, Crankshaft Position, and Traction were what came up when he took the car to the dealorship.
he's aiming it towards a bad pcm, which i disagree, and i think its either a bad wiring harness or 80% certain thoese parts that came up on the SEL light did go bad all at once. he also has a new crankshaft position sensor ready to install, but wasnt certain on where the 2 knock sensors are. i told him one's located in the front and the other in the rear, forgot exactly where they lie though. if anyone knows or has heard of this issue please let me know so i can tell him. thanks in advance.

btw, his car's mostly stock, will the pcm is stock for what i know of.

[BNaylor]

I agree. It may not the PCM. Have him replace the crank position sensor first. The knock sensor codes will probably go away so I would not worry about them for now. They do not normally go bad. The knock sensor module in the PCM is another story. After replacing the CKPS be sure to reset the PCM. Also, check the wiring harness at the ICM/Coil packs. Have the ICM module tested since it develops the signal for the tach after receiving the 18X pulses from the CKPS. Good luck!

[fst100]

sounds like an idea, thanks baylor