1999 Chevrolet Lumina – Code P0327 Knock Sensor

I again took a break from this knock sensor code problem, because I had hit a dead end. This was a tricky problem for me to solve, but with inspiration from Eric and members of this forum, I decided to give it one more try…

To review, after researching all the possible causes for a P0327 code using repair manuals and Websites, and not having access to a good scan tool, I did the following:

Replaced the knock sensor
Checked the wiring from the knock sensor to the PCM computer
Checked the connection at the PCM computer
Replaced the PCM computer that included updated software

All of this did not solve the problem. The car still had the check engine light on and the car had variable rpm’s at idle with slight hesitation during accelerations.

After reading the GM shop manual there was a small section that said the 24x circuit that included the crankshaft positioning sensor could affect the knock sensor signal.

I didn’t have too many remaining options, other than taking the car to an auto shop or start throwing parts at the problem, which I had already done. So I decided to replace the crankshaft positioning sensor.

When I pulled off the harmonic balancer the crankshaft positioning sensor was hard to find. It was complete covered in oil and dirt. It looked as if oil was leaking past the crank bolt and it was throwing oil on the sensor. I might have been able to clean the outside of the old sensor, but I decided to just install a new one.

Installed everything and put about 50 miles on the car. No check engine light. And the idle is now steady. It’s weird how a malfunctioning crankshaft positioning sensor would cause a knock sensor code. Where was the crankshaft positioning sensor code??? I gave the car another test and took the car in for a smog check. The car passed the test with no problems… Thanks to everyone for their help! 🙂