Old code P0135 , New code P0327

[Horsehammerr]

Got the old P0135 - Bank1 Sensor1 ( dang O2 sensor ) , combined with P0327 - Knock Sensor 1 Circuit Low Input Bank 1 or Single Sensor. The second code has me stumped. Can a bad O2 sensor cause low voltage to the knock sensor ? I really don't know what to make of this reading. I will for sure put new O2's in but, is my knock sensor bad or is it something else ? My Voltmeter is showing a little low charge, is this a sign of a new alternator in my near future or some other Grimlin ?

[roadrunner]

P0327 from the 01 manual: The knock sensor (KS) produces an AC voltage at all engine speeds and loads. The powertrain control module (PCM) then adjusts the spark timing based on the amplitude and frequency of the KS signal. The PCM uses the KS to calculate the average voltage. Then the PCM assigns a voltage value. The PCM checks the KS and related wiring by comparing the actual knock signal to the assigned voltage range. This code will set if the KS signal is outside the assigned voltage range or is not present.

All that being said the book then launches into a rather lengthy set of diagnostic procedures primarily consisting of checking for open circuit (with ohm-meter) through the knock sensor as well as for poor connections at its wiring connector, shorts to ground, and even hooking a DMM set to 400 AC hertz scale to the knock sensor and tapping the block with a metallic object and watching for a fluctuating frequency to check operation. As always it also says to clear the codes and see if they reset after diagnostics and possible repairs are performed.

Hopefully the operational explanation or perhaps the brief diagnostics listed here will help you. As for the O2 codes being related to the knock sensor codes it's doubtful unless there was perhaps an extreme lean-out causing activation of the knock sensor IMO.

[Jongo88]

I went through the knock sensor thing. I just took a chance and changed it. PITA by the way.... That code never came back.

[Horsehammerr]

Thanks for the deep research Roadrunner. I'll try to understand and look at this from that information. Won't have the time until Wednesday, so I'll let you know then. Probably end up like Jongo88 and just change the KS along with the new O2's.

[Horsehammerr]

I'm not sure where this Knock Sensor is located . Can you show me ?

[Jongo88]

It's in the back of the block behind the intake under the distributor. You have to pull the distributor and the fuel lines to get to it. Even then it is a BIG PITA to get to. The main thing is to make sure you torque it to speck
This is what it looks like.
http://www.google.com/imgres?imgurl=htt ... s%3Disch:1

[Horsehammerr]

Thanks Jongo88 ! I'll check it out tomorrow, my weekend.

[Jongo88]

I hope you have small hands unlike me....

[Horsehammerr]

I wonder if this knock sensor could be affected by the lower coolant temp from the 180 degree thermostat I run in summer time. Or do they just wear out like the wonderful O2 sensors we were Blessed with ? If so is there maybe a better way?

[Horsehammerr]

Does anyone have a picture of any kind showing the location of this Knock Sensor, I really like to see what I'm aiming at.

[Jongo88]

That would be very hard to get as you can't even see it..

[Horsehammerr]

I don't have a problem with removing the distributor , but I'm not sure about the fuel lines. What is the right way to do that part of the Knock Sensor change ?

[Jongo88]

They are easy. You have one bolt in the back and one nut in the front on the injector. They have rubber hoses in the back so you can move them to the side to get to the sensor...

[Horsehammerr]

Is this thing located under where the fuel lines go down the back of the block or where ? I just don't seem to be able to find it.

[Jongo88]

It is directly under the fuel lines. Once you pull the distributer you will see it. I could not see it myself untill I pulled it. I looked and looked and was stumped too.

[Horsehammerr]

Thanks for all your assistance in this search Jongo88 . It's always good to have at least one member pay attention to others problems. Especially when the directions are first hand experience .

[Jongo88]

Any time bud. I'm just glad I can help. If you where close to me I could realy help. Now that I have done it, it would not be to bad.
The hard part is getting the bolt started with the wire harness in the way. Just make sure you torque it to specks.
I don't remember what the torque is. It mite be 20 inch pounds but it has to be right.