Kinda caught between a rock and a hard place. The engine block was replaced because of some water damage. After getting it back, I had a problem with the Over Drive relay - the dealership couldn't find anything wrong. And thanks to you guys, it was just the wire connector falling out. :cheers:

Now I get a "Service Engine Soon" light while 'cruising' at 85 mph. It's a code 43 - and thanks (again) to this site, there was a recent post about codes. I knew about the paper clip trick. I saw the site with the codes. I pulled a 43.

The Codes Site says "knock sensor - replace or check wiring". Is this something that could be a result of the block being replaced? Is this something I can check? Where is it, so I can check to see if the wiring is in place?

I called the dealership about it and I agreed to clear the code and try to re-produce it. The "being caught between a rock and a hard place" reference above pertains to this: if something goes wrong on the car how can I attribute / prove it to be due to the work from the dealership? It's a tough thing to prove. :confused:

 

My first thought is that if the block was replaced, they either botched the connector OR they tightened down the knock sensor too tightly OR used sealant on the threads.

The botched connector is self explanatory. If the knock sensor is tightened down too tightly, the outer housing will separate from the inner housing and the sensor will be damaged. These things are supposed to be tightened in inch-lb, not foot pounds. The last thought is that there is too much sealant on the threads, reducing it's sensitivity so much that when the computer runs it's self test and advances the timing to where the knock sensor is supposed to sense knock, it doesn't.

The knock sensor is screwed into the passenger side block, in front of the starter and hidden from above viewing by the exhaust manifold. It has a blue wire running to the ESC (electronic spark control), which is mounted by the blower motor on the passenger side (opposite of where the battery is on the drivers side).

The computer does the previouslyt mentioned self-test at 194 deg F. If the code doesn't set before that, it is likely due directly to the knock sensor itself or the wiring to the ESC. If the code sets before 194 deg F, it is likely a problem in the ESC module itself (different from the EST module).

Check under the Tech Tips section. 65Z01 talks about upgrading the ESC module. This will help in the future, but it might not help if the sensor/wiring is the culprit. Good luck! -Matt-

 

Matt nailed it head on pretty much.When i replaced my engine,I started getting that code 43.Myknock sensor wasnt grounding for 2 reasons on the block.One,It had silicone on the threads and 2,they spray painted the block too thick with black paint.I used some sand paper to take the paint off that hole for the sensor,cleaned the silicone off and put the sensor back in.
Cleared the codes and the problem was solved.

Btw,I had to screw my knock sensor ALL the way in before it would register the self test knock.For some reason, the factory torque setting as well after cleaning wouldnt work,so I kept tightening it until it did work,and that was at the last thread.
The hole was a little messed up and wasnt retapped correctly at the machine shop.

Btw,it helped I had a scanner..while the car was running,I was able to tap the exhaust manifold with a hammer to see if it could hear the knock..when it started to register the knock from the hammer test,that was when I had screwed the knock sensor all the way in and knew it was picking it up now.

It was more trial and error for me to fix but having the scanner saved me alot of time.
:)

 

Since you already had a connector problem I would first check the connector to the knock sensor; it's a single wire connector same as used on the aux fan sw.

If you have to remove the knock sensor you could use a little anti-seize on it's threads since it's a conductor and would assure a good seal.

 

First is it retarding your timing between 4 and 20 degrees if it's (yes);* Disconnect knock sensor,* Ignition "ON",* Using a DVOM, check voltage between harness CKT 496 and ground.* Voltage should read between 4-6 volts. Does it? ...(yes) * Check resistance of knock senser by connecting Ohmmeter between senser terminal and engine block.* Should be between 3300 & 4500 Ohms. Is it? (yes) * Check harness and senser connector. If OK:* Remove ECM and be sure Mem-Cal is properly seated into ECM. If OK:* Replace Mem-Cal.----P.S. To clear codes dis-connect battery ground cable for a couple of minutes


[Modified by Intimidator454, 8:41 PM 12/20/2001]

 

OK if you checked the knock senser ckt. 496 and the voltage doesn't read between 4-6 volts the next question is; * Less than 4 volts,* Ckt 496 open, shorted to ground, or faulty ECM. :yesnod: :cheers: If the answer is;* Over 6 volts,* Check for Ckt 496 being routed too close to secondary ignition wires, or Ckt 496 shorted to voltage or faulty ECM. :boxing Hope this helps you...it's straight from the service manaul.


[Modified by Intimidator454, 8:39 PM 12/20/2001]