How do I (a laymen) change the mask ID byte from $EE to $AA?

hillbilly25177 · Post by **hillbilly25177** » Sat Sep 29, 2007 9:19 am

I have looked at a million posts with the bad checksum issue and I don't know how you guys are changing the mask ID byte.

I am also worry of just changing the $EE checksum because this doesn't always seem to fix the problem and if there is a way to fry my ECU I am guaranteed to find it.

A step by step process to explain this would not only be great for me but to a lot of your users that ask this question.

I know that this gets old to someone who understands whats going on, but to the average guy trying to tune his car it can be scary doing a operation that can fry the ECU, especially if its your daily driver.

Thanks for your patience with this,

Six_Shooter · Post by **Six_Shooter** » Sat Sep 29, 2007 7:45 pm

What equipment are you using?

Real Time emulation?

hillbilly25177 · Post by **hillbilly25177** » Sat Sep 29, 2007 9:19 pm

95 Caprice $EE strategy, Tunerpro and ALDL cable is the setup I want to use, still have not bought the cable just playing with the software and reading posts.

Does one checksum change work for all $EE ECU's (I actually have the L99 4.3 but have heard they use the same strategy)?

I don't want to make it any more complicated than possible, would unchecking the checksum flag in the tune take care of the problem?

I just want to take every precaution in avoiding a chicken fried ECU.

Thank you for the help

Six_Shooter · Post by **Six_Shooter** » Sun Sep 30, 2007 6:43 am

The ALDL cable is for datalogging.

You will need either an Ostrich or a Burn 1 (or silimar equipment) to either tune in real time (Ostrich) or burn EEPROMs datalog and re-burn (Burn 1).

I recommend the real time emulation route as it is much quicker and you can see changes as they take place. After you get the tune you want, then burn the bin file to an EEPROM, through a Burn 1 (or similar).

The checksum disable is only for real time emulation, in a static setting (using EEPROM only, checksum disable makes no differnce in the way it runs.

hillbilly25177 · Post by **hillbilly25177** » Sun Sep 30, 2007 10:39 am

I have a 94-94 LT1 capprice $EE strategy, I thought this type of ECU is the only one that does not require a burner.

My main issue is not frying the ECU, I know there are posts on here about it but they offer several solutions ( changing the checksum, changing the mask ID to AA, getting the fixed definition file or disabling the checksum flag in the tune ) and I would like to hear what someone that has done this would recommend before I jump in and F it up.

Thanks, I know that answering post that have been covered already is seemingly a waste of the really slick guys time on here its just that there's so much at stake if I screw it up.