stupid knock sensor code P0327

[kozzo]

So I just got this 03 Alero, and after sorting out all the bad mechanic work (various fasteners undone, heater bypass line not bolted and disconnected, spark plugs left un-tightened) I got it started up and running. It had a history of overheating, and I fixed all that. Now I'm throwing the P0327 code. I checked for 5 volts at the sensor wire, and nothing. I traced the wire back to the PCM and tapped off the wire there too, and still nothing
Am I looking at a bad PCM, or would there be something causing no voltage at this circuit? I ran a search on these forums, and found one guy had a bad O2 sensor, but I'm not throwing any other code. Ant help is much appreciated
Kozzo

[a.graham52]

o2 and knock sensors are two different things. what year and engine?

so i guessed and used a 99. code only used for 3400s. the knock sensor PRODUCES A/C voltage. not the other way around. without a scantool i suggest you unplug both ends of the circuit (ecm/sensor) and check for a broken wire with an ohm test. if nothing is found, install a new sensor. lot cheaper then an ecm.

[a.graham52]

edit. below is for a 99. after reading your into post i searched the daigs for 03 (both the v6 and the L4). all three are slightly different. all about the same principle. if you want more details, let me know. to test to GM standards you would need a volt meter that can do ohms and hz measurements.

[kozzo]

sorry, I posted year(03) but not engine- 3400
hmm, I was under the understanding that the knock sensor sends AC voltage, but the wire coming from the PCM sent 5 volts to the KS with a KOEO test, when the wire is disconnected, and about half that with the sensor connected(what I read somewhere else). I already replaced the KS. I have a multimeter, I will check the wire from the sensor to the PCM for continuity tomorrow. Just bought a scan tool also, just haven't figured out how to do anything other than read or erase codes yet

[kozzo]

guess i should have mentioned some symptoms too, aside from randomly running rough, once the vehicle is warmed up, and kicks the cel, it's hard to start, have to give it some gas for a while, and then the idle fluctuates

[kozzo]

Ok, finally did a check on the wire- it has continuity, and does not short to ground. I have read that the autozone knock sensors have proven to be not reliable- wonder if I should order a delco version from Rock auto before I give up and go to the dealership? suggestions?