code PO327 knock sensor #1

Indy · May 4, 2005

'99 Sierra 5.3L auto 4x4

My check engine light came on and when I read the code I got PO327 knock sensor 1 circuit low input. What would cause this? I washed my engine about 2 weeks ago and I read that the water can collect in the wells and cause corrosion on the contacts. Where would I find the #1 sensor so I can check it for corrosion or replace it? How much are they? Thanks

GM-Tech · May 4, 2005

The knock sensors (there are two) are under the intake manifold. The water and corrosion problem *usually* only affects the rear sensor, and your DTC is for the front sensor, but if you just washed your engine, I'd say it's a good possibility this is your problem.

bobcat5544 · May 4, 2005

MY 2000 WILL SET IT ONCE IN A GREAT WHILE, MAINLY IF I USE GAS FROM A LITTLE HOLE IN THE WALL GAS STATION. THE BEST THING TO DO IS CLEAR THE CODE AND SEE IF IT COMES BACK ON AGAIN. IF IT COMES RIGHT BACK ON THEN YOU MAY HAVE A SENSOR PROBLEM TRY GET GAS FROM A DIFFRENT GAS STATION LIKE QT OR SHELL, IF IT COMES BACK AFTER THAT THEN THE SENSOR MY HAVE PROBLEM.

IF YOU DONT HAVE THE SCANNER GO TO AUTOZONE HAVE THEM PLUG IN AND ERASE IT