7747 hiway spk/fuel mode

[rr]

Ok, just checked some of this stuff out. When in hiway mode, learn
on the aldl is off. The mpsi 9000 scanner also showed open loop mode
(this may vary depending upon which status bit the scanner uses).

When the knock test is done, yes, knock counts will show up on
the aldl.

Yes again, the values at 0xD54A are used for the knock/ESC test.
The ESC 43 test is actually a 2-parter. Knock is forced, along with
run-away knock checked for.

The hac has some errors in the comments of these test variables:

d54a & d54b together is the eng run time prior to test.
d54d is the retard degrees when either ESC 43 test fails.

If you haven't also added the esc_done patch, you may want to. This
patch sets the 'esc test completed' bit. This allows PE spark and
hiway mode to be operational without the ecm having to force knock.
Note the side effects of the patch: The coolant window and time
delay for PE spark are also bypassed.

BobR.


den Broeder, Ernst wrote:

> I've been playing with the hiway747 patch, and I'm not 100% sure if my
> calibration is actually even entering this fuel mode.  Is the O2 sensor
> value going towards ~100mV the only indication that the ECM has gone into
> lean cruise or will the 'learn control enabled' bit in the ALDL stream
> change accordingly as well from enabled to disabled?
>
> Are the values at 0xD54A the only factors used to determine whether the ESC
> test is done or not?   And will I see the knock counts increase on my ALDL
> scanner when this test is done?
>
> Thanks,
> Ernst
>
> ----------------------------------------------------------------------------

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org