At this point...

[jrpulley77]

I will resist the need to unload all this frustration on this keyboard. Rather than going around my butt to get to my elbow, I will ask this question and hope the answer is as simple as I seem to be, just lately.
What are the indications of a mem-cal chip going bad? Can it be tested? Or do you simply replace it and see if it solves the problem?
(e.g.) If I turn the key to "on", (engine not running) clear the codes and the knock sensor code re-appears, wouldn't that be an indication of a computer malfunction? Code 43 assumes the engine to be running in order to create the "noise" that the knock sensor "hears", correct?
The ECM is a "reman", and "tested 100%" according to Cardone. The "mem-cal" stick is the only thing I see that is still original. And there can't be detonation if the engine isn't running... So??? Suggestions?
Pulley

[Six_Shooter]

Posting the ECM and/or application will help. Different ECMs perform different tests at key on.

It may be that there is a knock sensor fault or circuit fault or a bad knock filter/ESC.

[jrpulley77]

the subject is a 1995 s-10/4.3/vin Z /tbi. the ecm # 16197427. Do you require the number from the mem-cal as well?

[jrpulley77]

In addition, now that it has cooled down, I will hook a voltmeter to the sensors and tap them to see that they are indeed working.

[ony]

this is interesting, had the same code on my coversion, thought it was my wiring job so I set it aside fore a while .my case it maybe a bad filter.but I don't have another one to see lf it is the filter.

[jrpulley77]

Greetings Ony,

This code 43 comes up on the code scanner as a knock sensor code, ECM or just plain "sensor". It is also one of the hardest ones to isolate. Stay tuned for more fun. If you've anything to add, I'd be happy to hear it.
What kind of "filter" are you referring to?

[Nasty-Z]

I would assume since this is a 4.3 S10 that it is a dual KS system ?

Have you measured the resistance of the sensors with the circuit disconnected from the PCM ?Should be around 8200 ohms each sensor IIRC for the dual KS system , single KS is 3900 ohms for the '7427 .

The PCM applies 5 volts to the KS circuit , have you disconnected both sensors and measured for the 5 volt reference at key on ?

Procedure is the PCM monitors the "return" voltage on the circuit on B15 , If it is not within spec for 10 seconds DTC 43 is set , engine does not have to be running , it tests this at key on from what I understand and have witnessed on my conversions.

From what you are stating,the DTC is set the instant you go to key on , my first guess would be bad KS board on the MEMCAL .

What is the 4 letter code on the MEMCAL you are using ? Where are you located ? I have a few 4.3 MEMCALs , don't know if I have what you need though.

TOM

[jrpulley77]

Wow! I'm IMPRESSED! I paid $95.00 to a GM Dealer yesterday and a TECH w/20 yrs. experience didn't even check the knock sensor resistance!

Please contact me @ jrpulley77@att.net. If you've got what I need I will pay YOU for it rather than an auto parts store. Contact me for phone #, I live in Palm Coast, Fl.