Discuss: Disabling DTCs Yes or No
#31
If you haven't had any problems, then definitely don't disable imo. Thanks Hiboost and others for explaining situations where more highly modified cars will always have issues because of the wide airflow fluctuations during launch control vs higher gears.
#33
Given your upgraded turbo, I would consider that pretty highly modified and I would just leave it alone if you don't have any problems (that is, leave the dtc's disabled and don't bother adjusting airflow tables). From what others have said, it's too hard to get those tables working in all conditions with a non-stock turbo. Just make sure your boost limit tables are set appropriately in case you do overboost.
#36
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You should still dial them in close so you don't get the ASC type "soft" code. I have that right now. You won't go into limp mode, but since your airflow tables are wrong it will still disable your asc, which becomes more of an annoyance than anything really, just need to restart your car.
I would say get them as best you can and then disable.
I would say get them as best you can and then disable.
As far as tuning out the torque and airflow codes as some people mentioned, I'm not so sure widening the gap or adding smaller values or more resolution would help. It would have to be about changing the logic of the ECU, like when and why it decides how much airflow is too much or too little. I don't understand why the ECU thinks that "not enough airflow" for a given RPM and throttle position requires a hard limp mode and 30% throttle with an erratic idle. Also, with the boost limit tables, I don't understand why it would need a "airflow too high" limp mode also. If there's too much airflow, there's going to be too much boost (overboost) and the load values will be too high which will trigger the boost limit fuel cut. Having the airflow limits do the same thing is a little redundant.
I don't know, maybe I'm just not thinking about it the right way. To me, it just doesn't seem like they're all that important. How many other cars have these types of tables in their ECU? I don't think even the previous Evos do, and there's plenty of them out there safely putting out anywhere from 500 to 900hp or more.
Last edited by ScottSpeed21; Jan 7, 2010 at 09:34 PM.
#37
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I don't think the ASC being disabled has anything to do with the torque and airflow limits. I think that's more about having a huge hit of torque when the turbo hits full boost and the stability control having a hard time knowing what to do with it all, so it decides to turn itself off.
As far as tuning out the torque and airflow codes as some people mentioned, I'm not so sure widening the gap or adding smaller values or more resolution would help. It would have to be about changing the logic of the ECU, like when and why it decides how much airflow is too much or too little. I don't understand why the ECU thinks that "not enough airflow" for a given RPM and throttle position requires a hard limp mode and 30% throttle with an erratic idle. Also, with the boost limit tables, I don't understand why it would need a "airflow too high" limp mode also. If there's too much airflow, there's going to be too much boost (overboost) and the load values will be too high which will trigger the boost limit fuel cut. Having the airflow limits do the same thing is a little redundant.
I don't know, maybe I'm just not thinking about it the right way. To me, it just doesn't seem like they're all that important. How many other cars have these types of tables in their ECU? I don't think even the previous Evos do, and there's plenty of them out there safely putting out anywhere from 500 to 900hp or more.
As far as tuning out the torque and airflow codes as some people mentioned, I'm not so sure widening the gap or adding smaller values or more resolution would help. It would have to be about changing the logic of the ECU, like when and why it decides how much airflow is too much or too little. I don't understand why the ECU thinks that "not enough airflow" for a given RPM and throttle position requires a hard limp mode and 30% throttle with an erratic idle. Also, with the boost limit tables, I don't understand why it would need a "airflow too high" limp mode also. If there's too much airflow, there's going to be too much boost (overboost) and the load values will be too high which will trigger the boost limit fuel cut. Having the airflow limits do the same thing is a little redundant.
I don't know, maybe I'm just not thinking about it the right way. To me, it just doesn't seem like they're all that important. How many other cars have these types of tables in their ECU? I don't think even the previous Evos do, and there's plenty of them out there safely putting out anywhere from 500 to 900hp or more.
Like I said .. the reference map is not changed thats why you guys are having the issues .. the reference map is used by evertyhing on the car ..
I can see the issue here is not understanding what each of the maps does that why there is seemingly no logic what you do to the maps ..
Once we can understand what these maps mean .. then you will know what to do with the maps so as not to trigger any codes ..
There are a few cel codes that is telling you you're making power .. and not adjusting them actually limits the amount of hp you can make..
On the MR its even worse .. all the codes that are disabled will pull down the torque going to the gearbox without you knowing ..
#38
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I've read this before but haven't seen a single MR owner do a before & after dyno pull where all they did was enable the DTC disable codes. What you are explaining is that even if you disable the codes it will still limit the power in the background in some manner without actually telling you which is pure evil. For the GSR I wouldn't think it's effecting power although the only time I would trigger the tables is doing a stationary launch and I only use that at the drag strip.
Last edited by Hiboost; Jan 8, 2010 at 10:49 AM.
#39
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Yes it does ..
Like I said .. the reference map is not changed thats why you guys are having the issues .. the reference map is used by evertyhing on the car ..
I can see the issue here is not understanding what each of the maps does that why there is seemingly no logic what you do to the maps ..
Once we can understand what these maps mean .. then you will know what to do with the maps so as not to trigger any codes ..
There are a few cel codes that is telling you you're making power .. and not adjusting them actually limits the amount of hp you can make..
On the MR its even worse .. all the codes that are disabled will pull down the torque going to the gearbox without you knowing ..
Like I said .. the reference map is not changed thats why you guys are having the issues .. the reference map is used by evertyhing on the car ..
I can see the issue here is not understanding what each of the maps does that why there is seemingly no logic what you do to the maps ..
Once we can understand what these maps mean .. then you will know what to do with the maps so as not to trigger any codes ..
There are a few cel codes that is telling you you're making power .. and not adjusting them actually limits the amount of hp you can make..
On the MR its even worse .. all the codes that are disabled will pull down the torque going to the gearbox without you knowing ..
No matter what I've done previously with the airlfow and torque limts or what codes and limp modes have been triggered, the ASC disabling itself always seemed independent. It made sense to me that odd torque outputs from hesitations in the power band would affect the ASC since it sees the throttle wide open, but also sees quick and erratic torque outputs to the wheels. It can't react quickly enough, becomes sort of "confused" as to what exactly is happening, and then shuts itself off.
That's what I make of it anyways...
I agree here, it doesn't make sense that it would still limit power without a code. It's not only the codes that are being disabled, it's telling the ECU not to check the airflow and torque tables anymore, effectively disabling the whole torque monitoring system.
#40
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Simple way to put it .. the DTCs are bypassed .. but the limits are not .. does that sound logical ?
Hiboost .. the MR is more restrictive .. GSR the only time I've seen a limiter kick in .. you are restricted to 12psi with no warning .. so if you've seen that .. then its one of the protection feature kicking in ..
#41
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No .. the routine sets a 0 or 1 based on the time (by putting FFFF you're just setting 65536 secs) .. it is just a timer delay to set the code .. it doesn't tell the ecu don't check the table .. other subroutines still check the same tables ..
Simple way to put it .. the DTCs are bypassed .. but the limits are not .. does that sound logical ?
Hiboost .. the MR is more restrictive .. GSR the only time I've seen a limiter kick in .. you are restricted to 12psi with no warning .. so if you've seen that .. then its one of the protection feature kicking in ..
Simple way to put it .. the DTCs are bypassed .. but the limits are not .. does that sound logical ?
Hiboost .. the MR is more restrictive .. GSR the only time I've seen a limiter kick in .. you are restricted to 12psi with no warning .. so if you've seen that .. then its one of the protection feature kicking in ..
The 12 psi limit is likely only possible with the ECU controlled boost system in place so that is probably why I've never seen that kick in. I believe that during the warmup phase of the engine it might restrict boost to certain levels before coming up to certain operating temps. Of course with my MBC in there I have to avoid high boost with my right foot.
Still it would be nice to document the power hit that the MR can experience on a dyno so we know for sure that it's doing something underhanded with the DTC's disabled.
#42
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No .. the routine sets a 0 or 1 based on the time (by putting FFFF you're just setting 65536 secs) .. it is just a timer delay to set the code .. it doesn't tell the ecu don't check the table .. other subroutines still check the same tables ..
Simple way to put it .. the DTCs are bypassed .. but the limits are not .. does that sound logical ?
Hiboost .. the MR is more restrictive .. GSR the only time I've seen a limiter kick in .. you are restricted to 12psi with no warning .. so if you've seen that .. then its one of the protection feature kicking in ..
Simple way to put it .. the DTCs are bypassed .. but the limits are not .. does that sound logical ?
Hiboost .. the MR is more restrictive .. GSR the only time I've seen a limiter kick in .. you are restricted to 12psi with no warning .. so if you've seen that .. then its one of the protection feature kicking in ..
One thing I'm wondering about if the limits are still there...before I disabled the codes, there were a couple different driving scenarios where I know I could hit a limp mode repeatably. I could hit both a soft limp mode, with the 1500-2000rpm idle, low boost and reduced throttle but the car would still be driveable. I could also hit a hard limp mode, with the erratic idle that sounds like misfiring, and severely limited throttle where the car would just completely die out and not be driveable.
After disabling the codes, I can go and try to intentionally throw those codes, and obviously nothing will happen, no limp modes or anything and the car will run perfectly fine. I guess that's the part I don't understand. If just the codes and limp modes are being blocked, and the actual limits are still there, why is there nothing being limited?
Also on a side note, I'm running the Cobb AccessPort with the Torque Monitor turned off via AccessTuner Race.
Last edited by ScottSpeed21; Jan 9, 2010 at 12:41 PM.
#43
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The 12 psi limit is likely only possible with the ECU controlled boost system in place so that is probably why I've never seen that kick in. I believe that during the warmup phase of the engine it might restrict boost to certain levels before coming up to certain operating temps. Of course with my MBC in there I have to avoid high boost with my right foot.
Still it would be nice to document the power hit that the MR can experience on a dyno so we know for sure that it's doing something underhanded with the DTC's disabled.
Still it would be nice to document the power hit that the MR can experience on a dyno so we know for sure that it's doing something underhanded with the DTC's disabled.
definitely not warmup ..
Originally Posted by ScotSpeed21
After disabling the codes, I can go and try to intentionally throw those codes, and obviously nothing will happen, no limp modes or anything and the car will run perfectly fine. I guess that's the part I don't understand. If just the codes and limp modes are being blocked, and the actual limits are still there, why is there nothing being limited?
Also on a side note, I'm running the Cobb AccessPort with the Torque Monitor turned off via AccessTuner Race.
Also on a side note, I'm running the Cobb AccessPort with the Torque Monitor turned off via AccessTuner Race.
I would agree transients are irritating .. but removing an indication that can protect / limit the engine without you knowing is like you said .. doesn't make sense ..
Whatever cobb has is already available in ECUflash .. they just renamed the functions ..
#44
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At the 2009 Buschur Shootout my airflow limits tables set off an error after having to abort a stutter launch due to the starting line not being ready for the next class of cars. It thougt the car was not making enough airflow and triggered limp mode as I backed off the line. I had to complete the entire quarter mile at 5 psi for a whopping 18.1 second pass @ 68 MPH, pretty anti-dramatic for the Evo X finals.
#45
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When there's a quick hit of airflow that goes over the limit, it would normally just pop the code and limp mode, but if you block it, obviously that won't happen and the car drives normally. But if there's something wrong with the tune or actual hard parts on the car that continuously puts airflow readings over the limit, it's still going to limit itself even though it can't tell you with a code.
So basically, when you turn off the codes, it gets rid of the annoyance of trying to tune out the transient codes, but can still limit power output if there's something really wrong and you'd never know about it.
I like friendly discussions like this...everyone learns