sparks11

codes 52,55.. when I finished the job I cleared the ecm so I was good to go,

before the fix had only code 52 now I have both

and do not know anybody with osci..

llcoolpass

you dont need oscilloscope, you're not a dealer.... im going to email you some things tonight, just hold your horses ... im watching some tv [prophecy crap on the history channel] at the moment lol

GEORGE_JET

Have you ohmed the harness to the computer? And checked resistance to grd? Disconnect the ECM and measure the wires to grd. If you are positive that the harness is good, and you have already replaced the sensors, the only thing left is the ECM. If so then you might want to consider purchasing a scope. Of course it will take a little while to figure out how to operate the controls on the scope. I picked up a used automotive one for $60 off ebay. It would allow you to see the signals generated from the sensors.

llcoolpass

i would definetely not ohm the harness to the computer. but do check for continuity from the harness end to end, if you want [might be hard to do ]. the ecm failure is a coded failure, but he doesn't have a code for that, so he's gotta follow the diagnostic steps [except for the oscilloscope, at the moment anyway] in the FSM which is on the WWW for download for free from certain sources

sparks11

I will check continuity on the harness to the ecm (a little hard to do but worth it at this point) so I can say if I have a short or no,I'm kind of suspecting that is a short what I have, first thing (and easy) I'm going to do tomorrow is check the plug that connects to the wire sensor and see if there's any crack on the wires over there..
I have a spare ecm and I already tried it and still the same codes so I can safely say ecm is ok

GEORGE_JET

I meant to say, disconnect the connector at the ECM, and ohm the harness out (back towards the sensors) Since the car is back together, I would suggest ohming the pins to ground. Since the Knock sensors should have at least 1 meg to ground, you should see at least that. Since you have already checked the sensor resistance, anything less would indicate that there is a wiring problem.
By unpluging the ecm, you could also look at the pins on the connector. I know that it is not all that easy to get to the ECM connector, but with the manifold back on the car it is not possible to get to the sensors. Unfortunately I do not have my schematics here at work, but I believe that the next step in their flow chart was scope the signal, and if it was good, to replace the ecm. Too bad you're any closer, I could have shown you how to run a scope, and you could have eliminated it being a wiring/sensor problem.

sparks11

ok so tomorrow thing to do:

check for continuity/ohm end to end (ecm connector to the end of sensor wires) less than 1 ohm means trouble on the wires

check the pins at ecm to ground anything less than 1 ohm means ecm trouble!

thanks guys!

GEORGE_JET

With both ends disconnected, you should see less than 1 ohm, end to end. Then measure one end to ground, that should read open. Any reading to grd would be bad.. Make sure the connectors look good.

GEORGE_JET

code 52.doc

This will help explain code 52

GEORGE_JET

code 52b.doc

Second half of code 52 doc,.

Keep in mind that if the senors resistance measures in spec, that does not prove that it is good. If it is out of spec, that proves that it is bad. It is a sutble difference, but significant. Do all of the resistance checks, and you will know if the wiring is bad (give the ECM connector a good visual inspection). Once you have verified the wiring, you will have to try installing replacement knock sensors, or ECM because unfortunatly you do not have access to a scope. As you see in the writeup, they include waveform patterns which show you what the amplitude and frequency of the signal should be.
The knock sensor is a piezo-electric crystal that generates a voltage when subject to vibration. The cable conducts the voltage to the computer, which then measures the amplitude and determines if it is in pre-define limits of normal operation.
If the voltage is too high,, or too low, the computer will set a code, enter a fail safe mode, retard the timming, and set the check engine light.

llcoolpass

yeah that's the FSM. nice work uploading that to help him out. :>

sparks11

thank you guys! I will check for those things as soon as get out of job and run to hardware store and buy some wire to attach it to the voltmeter to be able to check for continuity in both ends I will post numbers on each reading to describe better the problem

llcoolpass

OK, if this were my car, I would check the harness plugs condition.
I would check the sensor resistance.
I would check that the sensor is fully tightened to the block. Maybe the makeshift tool you used didn't tighten it adequately]
I would then replace the sensor if bad. I would then replace the harness plug, too, on both ,while in there, if I suspect deterioration.
I would check the harness as described in the FSM [the files George Jet uploaded are the exact same thing as the FSM].
For your case, it's very simple. You already know it's not likely the ECM. and both sensors being bad... come on.... most likely you just got coolant all over everything and now there's poor signal or grounding occurring... plus you might not have tightened it right or something..

sparks11

well I just finished testing all the stuff..these were the results:

I removed the plug from the ecm and then unpluged the other end meaning the knock sensors wire.. tested continuity and nothing...several times just to make sure and nothing no reading at all...( I tested the continuity between the ecm plug and the knock sensor plug )

tested the ecm to ground and the reading in both pins were 16.25


I may have bad wires..but what to replace or is any other test I need to do ?
I tried to follow the sensors wires but could do it a little bite only trying to see any crack or something...check the plug and two wires are very loose and almost out of the little hook in the middle of the plug.. but still holding kind of good..

llcoolpass

i dont get it, you have the tests, you should be able to follow them.... did you follow them exactly?

your english is a little rough around the edges which adds to my frusturation, but you're doing well believe me my spanish would be worse :-)

let me ask this, when you say you tested continuity, how did you do so? did you measure resistance or does your multimeter have a continuity mode that you used? have you checked the condition of the harness plug that plugs into the sensor? did you check the sensor for proper tighteness and for proper resistance spec?