What would cause this error code on my 7747 ECM (42.xdf)??

This error code has only recently started popping up (last week or so), but it's becoming more frequent lately....

Today, I put the throttle down about 3/5 of the way and almost as soon as I did that, the SES light came on and I received this error code......

I'm still learning the ins and outs of burning bins, so I come to you all with questions

1.) I can't remember the last time I replaced/checked the knock sensor, could this be the culprit??

2.) It seems that after I increased the target idle RPM vs. coolant temp, that I have been getting this error code... Thoughts?

Please, give me your thoughts, opinions, remarks, etc.

Thanks!!

 

Good possibility it is failing the forced knock test. Do a search on the TBI board using my name as the author along with "forced AND knock" (without the quotes) as the keywords. I have responded in several threads the details of the '8746 & '7747 knock tests (they are the same tests).

RBob.

 

Thanks RBob,

I reverted to the stock bin's values in the target idle RPM vs. coolant temp table, (taking my idle from around 725 back down to 650ish.) Since making a few runs around town, no error code, and nothing is appearing in the 'spark table' of WinALDL, as there was before.

Why would you want 'forced knock', that is confusing me.?.?.?

Thanks again.

 

Forced knock is used to test the ESC system. If the ECM advances the timing and the ECM doesn't see knock reported from the ESC system, then something is broken. Or, at least that's the idea of it.

Before thinking it is the idle speed table take a look at the qualifiers for the forced knock test. It may not have been run.

RBob.

 

RBob,

Thanks for the clarification on the concept of forced knock.

What do you mean by 'qualifiers' for the forced knock test?

Thankyou!

-Chase

 

Stuff like this:

Need to be within a certain coolant temperature range along with RPM & MAP. Also need to be in PE mode.

There is a patch that will bypass the forced knock test by setting the status such that the ECM thinks it already has been successfully run. Along with that patch is a lean cruise patch. Bundled together for the '7747 ECM.

RBob.

 

Thanks RBob,

Can you tell me more about this patch for the ECM to bypass forced knock test???

Benefits, cons, where to find this patch, how to install, etc..

Thanks so much.

-Chase

 

The patches can be found in this thread:
https://www.thirdgen.org/forums/diy-...an-cruise.html

The advantage of the esc_done patch is that the ECM will no longer force knock to occur. And PE mode SA will be correct (normal) all of the time.

This patch was one of the first patches I did for the '7747. I must say, on a performance engine the forced knock test is quite a surprise when it kicks in.

The lean cruise patch was actually done on a bet. Won 14 shiny pennies on that one.

RBob.

 

RBob,

Thanks for more very useful information.

Total n00b question coming your way:
How exactly do I load the patches into the bin I'm working with?

It says this, but I don't understand it really...:

"How to apply patch:

Copy your current bin to another file to be modified.

Enter the command:
s19_pat ESC_DONE.S19 0xD000 file2bepatched.bin
Note the last argument is the name of the file that you want
to be patched. This utility patches THAT file.

Make any changes to the thresholds and tables, calc the

checksum, burn a EPROM and test drive!

(NOTE: Make sure that you bring a known good EPROM on the

test drive. This is just for backup.)"

 

Need to open a Command, MS-DOS, CMD window and type the command in.

RBob.

 

I copy and paste the command from the text files into DOS, but I encounter this message:

" 's19_pat' is not recognized as an internal or external command, operable program or batch file. "

What am I screwing up here?

Thanks for your help.

EDIT- Although I am pasting this command from the text into DOS, I am also changing the bin file to the appropriate name...

 

Need to place the s19_pat.exe file into that same folder. Along with the esc_done.s19 file and your BIN. The s19_pat.exe file is an executable program. Written for MS-DOS but does run in a command window (gives an idea of how long ago I wrote this stuff...).

RBob.

 

I have placed the HIWAY747 unzipped folder into the TunerProRT directory, and also dragged a bin 'testpatch.bin' into the hiway folder

No matter what I'm doing I still encounter the same error message I typed above... I'm likely fudging some trivial detail somewhere, but I can't figure it out.

Any thoughts RBob??

Thanks

-Chase

 

See if this helps:


RBob.

 

RBob,

Thanks for helping me with this patch. There is an error in your text document however...

This: "s19_pat hiway_42.s19 0xD000 file2bepatched.bin"

should be this: "s19_pat HIWAY747.s19 0xD000 file2bepatched.bin"

Just letting you know about that minor inconsistency.

Oh, and I also had to switch computers to apply your patch. Turns out my 10 year old laptop has some DOS issues that prevented me from applying the patch...

Thanks again

 

RBob,

I know you guys put a lot of thankless effort into the DIY-PROM scene.
Seriously, thanks a ton for your willingness to help, and explain something to me.

It seems as if my truck runs significantly better with your HIWAY747 and ESC DONE patches??? Am I just imagining this????

 

I'm still getting the same error code, even with the patches installed.

I'm going to reinstall the patches, just to be sure I didn't goof that part somehow......

-Chase

 

I'm still getting the error code..

Frustrating.

I can disable the ECM's ability to set the CEL for the Err 43 Knock ESC in the flags/switches box, just as I did for the EGR function..

Would this help me in any way?

 

You shouldn't do that for either error code.

Disable the EGR by setting the EGR enable temperature to 150 C. That will prevent the EGR from being activated along with preventing the EGR malfunction diagnostic routine from running. If the EGR is never enabled then it can't toss a code.

And if the EGR is never enabled the ECM won't reduce the fuel and add timing when it does enable the non-existent EGR.

For the knock DTC, have you checked out the threads that describe the two tests that are run? Either of which will set code 43 if they fail.

The esc_done patch only bypasses the forced knock test. It still retains the run-away knock testing. Which is good as this is usually caused by something breaking. IOW: a bad sensor, ESC filter, or broken wire/connector.

You mentioned about the engine running better with the esc_done patch. Yes, this can happen. The PE SA is always available along with the highway SA. Also note that with an active code 43 the ECM reduces the spark timing which pulls power and reduces fuel mileage.

RBob.

 

RBob,

Thanks for correcting me about the EGR & ESC error code settings.
Someone on Fullsizechevy.com had told me that was how you disabled the EGR function.....

I don't have an option anywhere in TunerPro to set the 'EGR enable temperature'..... The only things I do have are this : EGR On ( % TPS) , EGR On (Speed), and Low MAP EGR On (MAP).. ('7747 ECM, $42 mask, ASDU bin)

What should these be set at to disable the EGR function?????

If I search for: run (AND) away (AND) knock (AND) test, I can't seem to find anything of much relevance to my situation.

Any thoughts?

Thanks,
-Chase

 

Setting both of the MPH enable parameters to 254 should disable the EGR. Can also set the two TPS% parameters high also. Between them the EGR shouldn't be enabled.

Here's some threads for the knock info:

https://www.thirdgen.org/forums/tbi/...-43-again.html
https://www.thirdgen.org/forums/tbi/...de-43-esc.html
https://www.thirdgen.org/forums/tbi/...code-43-a.html
https://www.thirdgen.org/forums/tbi/...code-43-a.html
https://www.thirdgen.org/forums/tbi/...-hiway-sa.html
https://www.thirdgen.org/forums/tbi/...i-problem.html

RBob.

 

RBob,

I have set the EGR enable parameters as you have described. Thanks again for clearing that up..

I have read the threads you posted (thanks by the way for that), and I'm not sure where to start in terms of trying to figure out my problem by process of elimination..

Should I begin by looking at the spark table in WinALDL???

EDIT- I have been mulling over this, which you posted in one of the threads:

"The cough is due to the added timing in an attempt to force detonation. When the detonation fails to appear code 43 is set. With a code 43 in place the ECM pulls ~ 8 degrees (cal dependent) of timing out all of the time.

The loss of timing is what causes the loss of power."

Whenever I go WOT, there is that "cough/hesitation/bog-down" (call it what you will) that you guys were discussing in that thread... Keep in mind this is after I applied the patches...

This makes me wonder if I am not getting the patches applied to my bin properly, and still having the ECM do the forced knock test?!?!?

Thanks!!
-Chase

 

Update- I've had to restart with a stock bin from Moates fileshare... For some reason, the bin I patched originally will not work anymore. I have tried patching, repatching it and burning the chip for it on several different computers, to no avail. The bin I first patched always gives me PROM error....

Is there a possibility that between transferring the bin across computers, jump drives etc. that it has been corrupted somehow??? Thanks.

I downloaded a fresh bin from moates and patched it last night, no PROM failure there.....

-Chase