- Moderator
- #1
KANE
Moderator
- Joined
- Mar 2, 2002
- Messages
- 3,244
- Location
- KY
- Corvette
- Dark Blue 1982 Trans Am(s): Polo Green 1995 MN6
Code 43- knock sensor, ECM, or MEMCAL? Could be any of the three, right?
Yep. After struggling with a code 43 for a while, it turned out to be base timing.
I went by the L82's timing setting for 6 degrees and needed another 6 degrees so that the self test would work. No more code 43.
Apparently, the ECM needed to get to 32 degrees of advance timing during the self test in order to induce knock, thereby baselining the system as fully operational. When it was set at 6 degrees, the ECM was never able to advance past 26 degrees- so t set a code 43 because it could not detect knock.
The ECM can advance 20 degrees on its own to perform the test. My GMPP engine calls for a max of 32 degrees at 3k rpm. It would never have been able to induce knock at a max of 26 degrees.
So, lesson learned when tuning a custom TPI swap... make sure the base timing is set in such a way that the ECM can induce knock- otherwise, you'll get a code 43 (knock sensor inoperative).
Yep. After struggling with a code 43 for a while, it turned out to be base timing.
I went by the L82's timing setting for 6 degrees and needed another 6 degrees so that the self test would work. No more code 43.
Apparently, the ECM needed to get to 32 degrees of advance timing during the self test in order to induce knock, thereby baselining the system as fully operational. When it was set at 6 degrees, the ECM was never able to advance past 26 degrees- so t set a code 43 because it could not detect knock.
The ECM can advance 20 degrees on its own to perform the test. My GMPP engine calls for a max of 32 degrees at 3k rpm. It would never have been able to induce knock at a max of 26 degrees.
So, lesson learned when tuning a custom TPI swap... make sure the base timing is set in such a way that the ECM can induce knock- otherwise, you'll get a code 43 (knock sensor inoperative).
