Hi ...This my first post here. I had some symptomatic missing or rough running with my Ford F250 V10 Super Duty 4x4 and took it in to the dealer. They couldn't find anything wrong so I decided it was time to invest in a scanner.

The only code I got was P0325, which is knock sensor malfunction. This could be my problem. Also I'm get really bad mileage like 8 mpg. I know the knock sensor plays with the timing and wonder what the computer does when it knows it has malfunctioned?

I can't find to much on this, my Haynes manual shows the location on the v8.

Does anyone have any experience with the problem or with testing and/or replacing the knock sensor? On the V8 it seems basically inaccessible without removing the manifold.
There is also, some evidence that my wiring might have been chewed, I'd like to know where the wires from the knock sensor are routed to.

Any thoughts or ideas are appreciated.
Thanks

 

I believe that code is for the knock sensor on the driver's side bank. Check the wiring condition.
The wire shielding connects to PCM pin 24/77
Knock sensor + wire to PCM pin 91
Knock sensor - wire to PCM pin 57
Let us know how you make out.

 

The sensor itself is located dead center of the engine valley, under the intake. They also used a jumper harness from the sensor to a connector on the main engine loom, that may or may not be used in your application.

 

Hanky

I"m a little bit of novice in this area. Am I checking for continuity from the wires attached to those pins to ground? If not, can you elaborate.

Sorry for the ignorance and thanks a lot for you reply!

 

You have to disconnect the plug from the sensor and remove the plug(s) from the PCM.
Then you connect your ohmmeter from one of the contacts in the sensor plug and probe the three locations at the PCM plug . One of those three should read "0" ohms or very close to 0 . Then do the same thing with the remaining two contacts. If the wires are intact they should read under 5 ohms. If not there is an in open in that wire. The pins on the PCM plug(s) are numbered and have to be read carefully since the numbers are small. This is a little past the experience of a novice and you may want to reconsider doing this yourself. Otherwise , be careful, go slow and if possible read up on PCM location and pin layout. It will help make the job a little easier.
If you decide to do this, when you reconnect all the plugs and wires and restart the vehicle it may run funny since the PCM needs to readapt to your driving habits.

 

Ah, perfect. Now I think I get it. Thanks for making it clearer.

I'll try to do this, but I've been under the impression that I could not see or touch the sensor as it was located in an inaccessible location, ie. under the manifold.

I've obviously got to do more research and exploring, but at least I know where I'm headed.
Thanks!