Got my IROC officially back on the road so I immediately started some more PROM tuning since I installed some Long Tubes, bigger TB, etc over the winter. I also removed the Charcoal Canister. For those of you who have removed your charcoal canister and want to have this change reflected in the PROM you are in for a surprise. Well, maybe not anymore since I am going to post my findings here:

I tried to disable CCP by unchecking the flag "canister purge when output energized" (hexaddy 18, mask 80). This didn't seem to work. DataMaster was still showing CCP DC's greater than 0%. All CCP events seem to be functioning normally. After messing around with various things I lookend in the hac and found a parameter that was promising. I set hexaddy 2EA (minimum CTS for CCP) to 300d F (150d C) and CCP was eliminated This worked like a charm. This paramater currently is not in the $8D TDF. I added it via the TDF editor. Anyhow - there seems to always be good and bad for everything. Well - there was some 'bad' for eliminating the CCP. I couldn't get highway mode anymore. Searching in the anht hac there are some Canister Purge Params several lines below LC83D that are related to hiway mode. Here is the relevant code ...

********************
* CAN PURGE PARAMS
********************
LDAA L0126 ; OLD CCP D.C.
CMPA $82E6 ; 50 PCT CCP DC.
BLS LC8A0 ; BR IF L.T. 50% CCP

Basically, if the DC is less than 50% then hiway mode won't engage . I set 2E6 to 0% and that didn't work . I think that this is because since you can't be less than 0% then the compare fails. I'm sure that a rewrite of the CMPA would fix this. But, for a quick temporary fix I set the MPH for CCP Enable to 50mph. I set the MPH for Hiway mode enable to 52mph. At 50mph the CCP begins to cycle and therefore, at 52mph the car gets into hiway mode.

Oh - and I also got around to trying Joe Georger's VEMaster in conjunction with a DataMaster log file on my car. All I have to say is wow. This program does everything for you. All you have to do is point it to a datamaster log file and point it to your current BIN. It scans the logfile and makes ALL of the adjustments to your VE tables. Talk about "point and click" simplicity. This program just about makes my Part Throttle VE tuning post above useless.

Tim

 

If you were using Source Code you could have dropped the whole routine. <g>
And all the other silly stuff in there....

Thanks thou for sharing that.

 

So true. In my defense all I can say is that I did so much work today on my car that I was way too lazy to spend the hours I would need to do that. I should just jump in and do it because it will only take hours the first time through. I did disassemble the AUJP to ensure that what I was looking at in the ANHT_HAC was the same as the base image I was working on.

Tim

 

I never had any real luck with VEMaster. Seemed it only made very, very small adjustments. I PREFER to use Traxions Part throttle VE Tuning post.

 

i tired the vephd from craig, it works ok, but for some reason i still find myself using a calculator and plotting it all outmyself.

 

That is the fix. That is what I had to do to make Highway Mode work when you remove the CCP. It was quite a while and I am positive I had posted this.

But if you change the compare so it recognizes 0% DC (stock the CCP must be H %DC. Change to NL and it works.

 

This code begins at address x'C861 on the AUJP BIN. If you edit Location x'C86E from "2338" to "2538", you will modify the code to change from a BLS (Branch Low & Same) to a BLO (Branch Low). If 82E6 is set to 0, it will no longer bypass as L0126 can never be less than 0.

The code will now look like this for AUJP.

Remember, ANHT is different from AUJP and offset by 8 bytes at this point in the code. I've tried to be as careful with the location addresses for the AUJP bin, but you should double check yourself.

 

Glenn,

Are you saying to change 2338 to 2538 because the opcode for a BLS is 23 whereas the opcode for a BLO is 25? If so, where does the 38 come into play? If I am totally off then how do you know to change 2338 to 2538. I have the 68HC11 manual.

Tim

 

The 38 is the "number of bytes" to jump if the condition is correct. I put it there so a person would be certain they found the RIGHT "23". If you don't see a "38" following the "23" then you have the wrong location (or you source code has been seriously altered).

I don't know if you do this, but for a "quick change", I will often use the EDIT BUFFER funciton of the Pocket Programmer Program to change the byte. I would just retype "25" over "23" at location "4861" in the buffer (remember that the code and bin are offset by x'8000).

Then, I would just save the buffer and re-read it with TunerCat, which will readjust for the proper checksum.

 

I finally got around to modifying the hardcode as per what Glenn had said to do. Worked like a charm. I now have CCP fully disabled and highway mode still gets commanded by the ECM (even though the CCP% is zero). Thanks Glenn!

Tim

 

what does it matter if the ccp is not disabled. What is the downside? I would imagine that the ecm makes 0 fuel/spark corrections for ccp. Maybe iac....?

 

Yo Glenn or Trax,

Just so I know, you cannot make that modification to disable CCP and retain HWY mode if you don't not have the TDF editor right? I can't do that with the regular Tuner from TC can I?

Just want clarification...

Thanks

 

Necro'd.

Is the hardcode still the only way to get rid of CCP and keep highwaymode?