That is the 'exact' problem with tuning a car using data collected from 3rd and 4th gear pulls only, with WOT on a dyno thinking you've done your job properly. It's just not the case.

 

In my response, I did say "unfortunately no one in the community fully understands the conditions that cause a P1235 code, and if they do, they haven't yet made this information freely available."

Regardless, I appreciate the explanation. However, I'd still like to determine how exactly to correct this problem without disabling these codes as some other tuners have suggested. I have since found a couple of threads on this, but they are still mostly full of speculation and suggestions to disable this code. The most interesting information I found so far agrees with what you said, and talks about airflow tables in the ECU.

The problem for me occurs in all gears, usually between 50-80% throttle. The car was fine with this tune/setup for 8 months, and without a change in humidity, temperature or barometric pressure, began showing up suddenly.

 

The airflow/TQ tables need to be adjusted...search around. Lots of people get it when its not adjusted properly.

 

Good thinking
I found disabling the codes limits the car somewhat ..
you don' the irritating CELs, but you aren't very fast either ..

 

If you do both, it makes power without CELs.

You've been quiet gunzo. Hope all is well


- Bryan

 

Sup Bryan .. busy .. work and kids

You actually don't .. well not on the MR anyways ..

With the capped CELs.. the ECU actually starts reducing torque..
And with you not being able to see it .. you don't know where or what to adjust..

Its a catch 22 ..hehe do it and you don't get the nuisance but you get restricted .. don't do it and you get the problems ..

 

I adjusted my torque and airflow limits up, and eliminated the problem I was having so far. I my have the issue crop back up when it gets cooler, but so far I am okay in the mid 50s, wich is winter temp here on most days, or warmer. I am not a fan of disabling things that tell me I am about to spend a big **** ton of money. I don't like things that stop me from doing it, I just like being told I'm going to, if that makes any sense.

 

Yes indeed. I have seen this first hand even with the CELs turned off. Reduced power, then adjusted tables, power comes back. Magic car....

- Bryan

 

I get the p1235 code too. My tuner is having trouble helping me out with it as I am a 3 hour drive from him. He says it is a problem with the accessport and needs to tune it with open source. Not sure why the problem is with the AP but I need it to be fixed ASAP.