Jump to content

PCM programming discussion/questions


zippy

Recommended Posts

You think they'll look there first and skip the "let's check the computer codes first" bit? (Even though there are no codes showing..)

Checking for codes will not reveal PCM programming. Your only worry here would be if they determined that the tranny was toast and then decided to check for PCM programming as a possible cause.

Link to comment
Share on other sites

  • Replies 66
  • Created
  • Last Reply
Question for you Edit guys.

 

Calculated Airflow vs. RPM vs. TPS (P1514 table) -- does anyone know what the units are in Edit? I am trying to convert the PR algorithm for updating this table for HPT and some guy with a turbo... HPT is g/cyl (so the top left cell is .7 in stock trim).

 

The algorithm says to calculate your PR [ (14.7 + boost psi)/14.7 ] and scale the table with that value, replacing any values < 500 with 500. Every value in HPT is < 500. Heck, they're all less than 2... Not having Edit, I can't figure out the relationship and no one at HPT seems to know.

 

I've also been told by 2-3 people that using this algorithm will not only remove the 1514 DTC but will help eliminate weird KR at WOT (It's worth a shot :P )

In Edit, the table is something like milligrams per cylinder arranged by %tps and RPM. Top row is 700 across; bottom left (0%tps,8000rpm) is 25.

 

Sounds like HPT shows the table in grams/cyl. So your 0 rpm row would be 0.7 across, and bottom left 0.025. If this is correct, then you can just scale the table as suggested and use 0.5 instead of 500 as the minimum.

Link to comment
Share on other sites

Thanks Deezel!

 

 

So the algorithm for forced induction (and I am just testing this now -- I do not make any claims that it is correct).

 

1) calculate your PR

 

PR = (14.7 - boost psi) / 14.7

 

2) In HPT, scale your calculated airflow vs rpm vs tps table by your PR [in LS1 Edit, take the PR X 100 and use mult %]

 

3) In HPT, apply a floor of .5 to all values (i.e. replace any value < .5 with .5) [in LS1 Edit, apply a floor of 500]

 

Voila. Done.

 

 

My first pass of testing left me very negative in LTFTs (-7.8 at idle and some idle smoking), but I had already adjusted the MAF table to shift the LTFT range into the -2 to -8 range. I feel from the testing (but haven't analyzed the data, yet) that I will have to scale the MAF table back 2% or so.

Link to comment
Share on other sites

You think they'll look there first and skip the "let's check the computer codes first" bit?  (Even though there are no codes showing..)

Checking for codes will not reveal PCM programming. Your only worry here would be if they determined that the tranny was toast and then decided to check for PCM programming as a possible cause.

So they would physically take it out and look at the "westers garage" sticker? (I knew I should have taken that thing off..) or start looking at the actual programming? Not trying to be a smart ass here..

Link to comment
Share on other sites

You think they'll look there first and skip the "let's check the computer codes first" bit?  (Even though there are no codes showing..)

Checking for codes will not reveal PCM programming. Your only worry here would be if they determined that the tranny was toast and then decided to check for PCM programming as a possible cause.

So they would physically take it out and look at the "westers garage" sticker? (I knew I should have taken that thing off..) or start looking at the actual programming? Not trying to be a smart ass here..

Did you get this checked yet?

My guess would be the dealer would check the PCM for codes related to the trans problems. And with a grinding noise, probably check the trans pan. If there are codes, they will usually fix that stuff first. If there is metal in the pan, they will probably drop the trans.

With all the aforementioned work keeping them busy, it is unlikely that anyone at the dealership would be checking your tune.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...