92 454 code 43

[black dawg]

92 k3500 454 manual. Truck has external esc module. My question is what does the ecm have to see to set this code? I am fairly familiar with how the 5.7 esc works, but the info I am finding says for the 454 it will set for too much knock. Does the ecm test the esc circuit like it does with the 5.7?

 

[eagle mark]

Each ECM may have a different test, what ECM?

Usually it's a forced knock test. After certain parameters are met it will add 11 degrees timing and if knock count is correct or above it passes. If not it adds 22 degrees timing... no knock counts and fail.

It's a horrible test and causes major havoc on built engines. When I do a chip on these I patch the test so it is done! No Forced Knock!

To make sure your knock sensor is working have engine running while data logging or scan tool and hit block with hammer, it should read knock counts.

It's usually a wire to or the knock sensor. FYI the knock sensor is different on 5.7L and 7.4L engines, some 454 do not even come with knock sensor circuit. 5.7L and 7.4L Chip for knock is again completely different.

 

[black dawg]

ecm is 8747, cant remember what prom though.

I messed with it a couple days ago, and you have to whack the block pretty good, and right next to the knock sensor to get any results. I will try another knock sensor, and clean threads and see what happens.

Do you know what conditions have to be met for the esc test to be carried out?

Thanks for sharing your knowledge on this stuff.

 

[eagle mark]

1228747 is $4F... seems even worse as it's only done during PE. Just when you need knock, right?

       ;------------------------------
        ; ERR 43 PARAM'S
        ; KNOCK DET ERROR
        ;------------------------------
LD5AD   FCB  255    ; 99.6% TPS PWR ENR BYPASS ASSUM PWR ENR CONDITION
LD5AE   FCB  128    ; 3200 RPM UPPER LMT FOR ERR 43 TEST
LD5AF   FCB  195    ; 81 Kpa LOWER LMT FOR ERR 43 TEST 
     ;
LD5B0   FCB  34     ; 12 DEG SPK PWR ENR ADD TO CAUSE KNOCK 
LD5B1   FCB  63     ; 22 DEG SPK PWR ENR ADD TO CAUSE KNOCK, 2nd MODE PE
LD5B2   FCB  2      ; 2 KNOCKS, KNOCK LMT MIN (12.5 Msec Period's)

Don't over torque the new knock sensor!

 

[black dawg]

Well, had a little time to mess with this. Put in new knock sensor, and now tapping on the block near the sensor will show knock. I have tested the wiring and tried another esc module.

Still get code 43

Driving with the scan tool I cant get it to show any knock counts, even with timing (base) advanced 8 degrees. I have had engines before that never would ping, even with lots of timing (but never pushed the timing to try to make them knock),. Is it possible that this engine just wont knock, even with the 22 deg added in the test?


prom is arpa if it helps.

 

[eagle mark]

Did you clear codes?

 

[black dawg]

I did clear codes.

Also, it will show knock counts while starting, and also if you give it a good rev while parked.

 

[eagle mark]

Knock sensor is working then?

Your playing with fire adding 8 degrees and trying for knock counts?

Not sure why you still have Error 43? Clear it and make sure it's gone before your drive.

Looks like the test only runs in PE = WOT, over 183F, higher then 81 MAP, more then 99.6 %TPS, so it takes a lot to get to the test?

It's one of the first things I turn off, the test, not the knock sensor, I'll check the knock sensor thank you and don't need an ECM forcing my motor to knock every time I go full throttle!

And just un-checking the Error 43 CEL is NOT how you turn off the test! Just turns off the CEL if test fails, ECM still forces motor to knock!