OK, I know code 43 has been covered a million times. What I need to know is, well, what is going on with my ECM. I have what I believe is the correct knock sensor, it will pick up a couple counts when you start the car, so I assume it is correct.

'727 running $8D.

Ok, I clear the codes with key on, no trouble codes. As soon as the engine is running, code 43 sets. EST Failure. I can clear the codes while idling, and c43 comes right back on. I have no SES light at this point, when c43 is set (per TP bit status window). I have verified that c43 is set up the same as the other trouble codes flags in the ALDL Definition Editor, that is to say, Bit Set shows 'Error' and Bit Clear shows 'OK'.

Now, If I clear the codes, and uncheck the DTC 43 bit (Address 024B, bit 4), I get an instant SES light, but the car seems to run better (ie, its not cutting out and hesitating under slight acceleration). So can anyone explain this to me, am I not seeing something obvious here?

 

Well, from reading some other posts, it looks like the few counts I get at startup are part of the ESC test that the ECM performs.

Looking at the datalogs, I have no knock counts (besides the initial few) and the ECM pulls up to 20 degrees of timing under certain rpm/loads. Is this protection against a missing KS. I'm wondering if the KS is bad, ECM does not pass the test on startup (don't know how the few counts are recorded in this case though), hence the immediate code 43, and resorts to pulling timing as a safety measure.

Also, thinking back, I remember when I had the engine out, I tried to remove the KS and it just spun, ie the head (where a wrench can connect) spun but the threads did not back out, because the two 'halves' broke loose. Not sure what is inside, but wondering if that may have damaged the thing. Anyone care to comment?

 

Replace it

It is broke and causing the majority of your issues

later
Jeremy

 

Thanks for the confirmation. I actually didn't remember about that until after I posted the first time, then I got to thinking...

 

Replaced the KS with 3.9K unit, the previous one was 98K. Works fine, no code 43, no knock retard, but it still cuts out bad.